MS. SUSAN PAGEThanks for joining us. I'm Susan Page of USA Today, sitting in for Diane Rehm. She's away on a station visit. The Supreme Court will hear arguments tomorrow on that controversial Arizona immigration law. It requires police to question and detain anyone they suspect is in the United States illegally. The court's decision, which may come in June, could have far-reaching consequences for immigration policy in the 2012 presidential contest.

MS. SUSAN PAGEJoining me in the studio to discuss the Arizona case: Angela Kelley of the Center for American Progress, Jonathan Turley of the George Washington University Law School, Tamar Jacoby of ImmigrationWorks USA, and Steven Camarota of the Center for Immigration Studies. Welcome to you all.

MS. ANGELA KELLEYThank you.

PROF. JONATHAN TURLEYThank you.

MR. STEVEN CAMAROTAThank you for having me.

PAGEWe're going to invite our listeners to join our conversation later in this hour. You can call our toll-free number, 1-800-433-8850. Send us an email to drshow@wamu.org, or find us on Facebook or Twitter. Well, Jonathan Turley, let's start with you. What does the Arizona statute say, and what's really at issue, the core of the issue before the court?

TURLEYWell, on the most basic level, the question is whether a state law conflicts with federal law, if it seeks purportedly simply to enforce the federal law. Immigration is an area that has long been largely occupied by the federal government but not entirely. The Supreme Court has in the past recognized so-called concurrent jurisdiction of the states. But in this case, Arizona passed a law that essentially has its officers enforcing federal law.

TURLEYAnd that has created a very interesting series of arguments in court because the administration is faced with a law, the immigration law, that does not expressly preempt or push aside state law, so the question became implied preemption. And the administration had to argue that the state law conflicted with the federal law even though it was purportedly just enforcing it. That led the administration to argue in courts, something maybe quite unpopular with some citizens, that it really has a policy not to deport all legal immigrants, that it focuses on so-called dangerous legal immigrants.

TURLEYAnd that has led to this colossal fight in the Supreme Court. Does it constitute a conflict for the state to say we're going to enforce federal law when the federal government is saying that's not how we really want to enforce it?

PAGEThis law was passed in Arizona almost exactly two years ago. Two years ago, this method prompted some other states to pass similar laws. What have lower courts ruled as this has come up through the system?

TURLEYWell, as in the past, the federal courts are highly deferential to the federal government. This is a field that is saturated with federal jurisdiction. It's also a field that has bound up with it foreign policy issues that concern the administration. For that reason, there's a certain deference. Now, having said that, the Supreme Court has also had a presumption in favor of concurrent state jurisdiction.

TURLEYSo the Supreme Court doesn't like assuming that states cannot pass laws, particularly in an area where the Congress itself is recognized concurrent jurisdiction. So it goes to the court with very strong arguments on both sides.

PAGESo, Angela Kelley, you think this law is unconstitutional. Why?

KELLEYI do and -- because this is an area that the federal government has been very clear that it seeks to control. And the Arizona, the Alabama, the Georgia, South Carolina laws all go well beyond what the federal government would -- had said the states can do. And there's just some very serious practical implications that we've seen play out in these states that should give us pause. I think that these laws are on a collision course with the demographic changes on this country, and this is what I mean by that.

KELLEYWe know that -- I mean, although this is about unauthorized immigrants, they aren't actually aliens. You can't tell looking at them whether they belong here or not. You can't tell looking at somebody whether they're carrying the right immigration papers any more than you could tell whether I paid my taxes last week. I did. And so when you have a state like Arizona where 30 percent of the population is Latino, where you have 65,000 Mexicans who enter Arizona every day to do business, enter illegally, you can't tell simply looking at somebody whether they belong or not.

KELLEYAnd this invites racial profiling. And that runs just smack against core principles about what this country stands for. You shouldn't be judged by how you look. You shouldn't be judged by how you speak or how you dress.

PAGESo, Steven, I know that you disagree with that. Why do you think this law should be allowed to stand?

CAMAROTAWell, I certainly agree with Angie that people should not be -- should singled out. There shouldn't be racial profiling. Yes, it's true that the Pew Hispanic Center has estimated that something like 98 percent of illegal immigrants in Arizona are Hispanic, about 94 percent are thought to be from Mexico. But the law itself explicitly states that you're not supposed to use appearance, national origin, ethnicity.

CAMAROTAAnd the way it works is if a police officer pulls you over and he asks for your identification, which, of course, will happen, if the person has no identification, can produce no U.S. identification, then the question is -- are -- is there beginning to be reasonable suspicion the person might be in the country illegally? Then the officer can inquire about that. And the person, if they are, then they can proceed from there.

CAMAROTASo it's really just a kind of common sense thing. Determining identity is something you always do in a traffic stop or any other time. Officer issues a citation, the person has no identity, and there's reason to think they're in the country illegally. They just pursue it. It's called reasonable suspicion. It's well defined in the law, but it's also well defined for everything, from jaywalking to drug cases, murder, robbery, what have you.

CAMAROTAAnd that's all this law basically does. And the other thing it does is it requires you, if you're not a U.S. citizen, to have your immigration documents with you. Federal law has required it since the 1940s. It's well established. It's not considered onerous. Every country does that. And Arizona just has a law that mirrors the federal law, so, although there's a lot hyperbolic statements about it, it's just common sense. And it's just (word?) a kind of incremental approach to helping the federal government enforce immigration laws.

PAGESo, Tamar Jacoby, what do you think? Do you think this approach makes sense?

MS. TAMAR JACOBYI agree with every word that Angie Kelley said. I think the Arizona law doesn't necessarily mirror federal law. I think it does go in a somewhat different direction. And I -- my ideal preference would be that the court strike it down. But I look at the universe, and I see that the states have gone so far in the direction of -- the pendulum swing has gone so far in the direction of a federalist revolution with states taking power into their own hands.

MS. TAMAR JACOBYAnd I see a Supreme Court that I believe is inclined to -- does have an inclination to like federalism and to agree with states rights. And so I see the potential that the Supreme Court is going to give at least an amber light, if not a green light. And I think if the Supreme Court is going to give an amber light, I would like to see them give an amber light to a broader array of state enforce -- of state immigration laws.

MS. TAMAR JACOBYWhat we're seeing in the states now are almost exclusively enforcement actions. But when I travel around the states and talk to legislators, I see a hunger to do something more constructive, to figure out some way to deal with the unauthorized immigrants in their state, to fill -- to figure out some way to bring in legal workers. And I think if we're going to have a situation where the states are experimenting, I'd like to see their freedom for the states to experiment in constructive ways beyond just enforcement.

PAGEAngela.

KELLEYYeah. I mean, I agree with Tamar that that will be the instinct of some states, right? So if Arizona is upheld, then the injunctions in part will at least go away in South Carolina, Alabama and Georgia. So those laws are going to go into effect. It's going to scare the community, and you're going to see people leaving the states and going to friendlier states. And I think what Tamar is saying as well, then we'll have other states that might say, I'm going to give you a state green card.

KELLEYI'm going to let you live here, and I'm going to let you work here. You could see a state like perhaps California going in that direction or in Illinois. So you could begin to imagine a map where some states in the U.S. are saying, come on in. Come on in and work. Come on in and pay taxes. We like you here. And other states are saying, stay the heck out. I don't want you here. You have to be able to show papers that you're here legally the way Steve thinks is just so easy for people to do.

KELLEYI mean, I don't carry documents that show that I was born here. Anyway, that's a patchwork of laws, and that's a country that makes me feel very uncomfortable where you've got some saying come in, some saying go out. And that's exactly what the Articles of Confederation why we -- that's why we changed them, right, so that we would have one national voice, one united states and uniform policy on immigration.

PAGEJonathan Turley, legally speaking, does that patchwork argument -- is that something that would be of concern to the court?

TURLEYI think, certainly, it is an argument that would concern the court. We have, in many ways, a traditional lineup here between the left and the right of the court. One of the most interesting factors is that Justice Kagan has recused herself because she was the former solicitor general to President Obama. Also, looming in this case is a case called Whiting. This is a case that the court just decided. It looked at the Arizona law but at different aspect.

TURLEYAnd in that case, four justices said strongly agreeing with -- this was with Justice Robert -- Chief Justice Robert's writing that they want to impose a high standard to set aside state law. And notably, the only one of the conservatives not present in that -- with that statement was Justice Thomas, who's expected to be an ally. So what we're looking at is if it ties 4-4, then the Court of Appeals' decision is upheld without opinion, and it's a win for the administration.

TURLEYIf Kennedy votes with the conservatives and Thomas, then it's a sweep. It's going to be a majority for striking down the law. And then I think there'll be significant ripple effects. But Kennedy, as always, is very much in play. Kennedy is very sensitive about racial issues. So you have on one hand Kennedy saying in Whiting, I want a very high standard, agreeing with Chief Justice Roberts. And in the past, however, Kennedy has also been very concerned about racial issues.

TURLEYThe thing to remember is that the court's going to be focusing not as much on the individual provisions as to reasonable suspicion and how this plays out, as the more fundamental threshold question of what constitutes implied preemption and can the state even legislate in this area in this way.

PAGEJonathan Turley, he's a professor at The George Washington University Law School. And I'm also joined in the studio with Tamar Jacoby, president of ImmigrationWorks USA -- she's also a fellow at the New America Foundation -- and Steven Camarota, director of research at the Center for Immigration Studies, and Angela Kelley, vice president for immigration policy and advocacy at the Center for American Progress.

PAGEWe're going to take a short break. And when we come back, we'll be joined on the phone by the Kansas Secretary of State Kris Kobach, who has been one of the architects of these laws and a big defender of them. We'll be glad to talk to him and ask him some questions, hear his thoughts. And when we come back, we'll go to the phones and take some of your calls and questions, 1-800-433-8850. Or send us an email at drshow@wamu.org. Stay with us.

PAGEWelcome back. On the phone with us now, the Kansas Secretary of State Kris Kobach, a chief legal architect of the efforts by states to combat illegal immigration. Mr. Kobach, thank you so much for being with us.

SECRETARY KRIS KOBACHMy pleasure.

PAGEYou know, we've got this argument before the Supreme Court. Why would you argue that immigration isn't really a federal matter that should be left to the federal government to enforce?

KOBACHWell, because the precedence of the Supreme Court have long held that states can act on the field. It is, of course, the primary responsibility of the federal government, but states can play a secondary role, and that is the question here. And as Professor Turley accurately mentioned, there are some earlier precedence from 1976, where the Supreme Court upheld an Arizona law affecting the employment of illegal aliens.

KOBACHAnd then just last year, when the Supreme Court upheld a separate law that Arizona passed in 2007 concerning the employment of unauthorized aliens, again, the Supreme Court ruled in favor of the state. So the narrow question here is whether this particular Arizona law fits within the window that Congress has left open for state action on the field.

PAGEWhat do you think about the argument that the Obama administration is making, though, that the proper enforcement of immigration law is not to try to find every person who is here illegally, but rather to set some priorities in terms of going after illegal aliens or undocumented workers who might pose a special threat?

KOBACHWell, you've asked a question that goes to the very core of the Obama administration's case. Normally, in a conflict preemption case like this, the challengers to the state law would say, well, here's an act of Congress that conflicts with the state law. Therefore, we win the case because Congress -- a state may not enact a statute that is in conflict with federal law. But, in this particular instance, there is no such federal statute that says anything even close to saying that Arizona or another state cannot do this.

KOBACHAnd the Obama administration has gone to the argument you just iterated, which is, well, it conflicts with our priorities. We in this administration don't want to enforce the law that's been on the books for more than 50 years that an alien must carry certain registration documents with him or her. We don't want to enforce other provisions of federal immigration law so aggressively. We'd like to just focus on certain illegal aliens.

KOBACHThe problem with that argument is that then you're trying to say that the whims of a particular executive branch can have the effect of displacing the states from the field, and our Constitution doesn't read that way. The Supremacy Clause says an act of Congress must be used to displace the states or a treaty ratified by Congress, or the Constitution itself. The executive branch doesn't have the power to unilaterally preempt.

KOBACHAnd I think that argument is going to be one of the most important arguments Arizona makes, and the argument you just made is the core of the United States' position in the Obama administration.

PAGEDo you have any concerns that laws like the Arizona law lead to racial profiling of Hispanics who are here legally and some of whom are citizens?

KOBACHWell, I'm not concerned in this particular case because we drafted the Arizona law to expressly prohibit racial profiling. Indeed, there is -- there are four different sections where the law makes clear that it cannot be enforced with regard to a person's race or ethnicity or national origin. And as Steven was pointing out earlier in the show, there are many, many factors that are not racial in nature that can be used, and are used, dozens of times every day throughout this country to determine whether there's reasonable suspicion that a person is in the country unlawfully.

KOBACHFor example, some of the ones that courts have recognized are if the individual does not possess any documentation of any sort -- photo ID, non-photo ID -- has nothing on him, that's one factor that go into the calculation. If the individual has evidence in his clothing, like he's wearing dusty clothes and appears he's been on a journey across the desert, that is a factor. If the individual is traveling on a known alien smuggling corridor, that's a factor.

KOBACHThings like that, which have no reference to a person's race or skin color, can be used by an officer in saying, well, taken together, these factors suggest that this might be a person unlawfully in the country. I'm going to call the 24/7 hotline that the federal government established back in the '90s and see if the person is here legally or not.

PAGEMr. Kobach, this is a legal issue, of course. There are also political implications, and I wonder if your concern this is going to be damaging to Republican hopes of winning back the White House, given the reaction from a lot of Latino voters in the United Sates.

KOBACHI don't think it will. You know, I think people often oversimplify, or they try to judge all Latino voters and their preferences, you know, en masse and say, well, Latinos think this and Latino think that. And I think that's actually, you know, very disrespectful to Latino voters who have a wide variety of views. And if you look at specific issues over time, like referendums on the ballot in Arizona and other states, you see that the Latino electorate breaks down similarly, not exactly the same, but similar to other factions of the electorate.

KOBACHAnd so there are many Latino voters who say, look, you know, my family came to this country two or three generations ago legally. We played by the rules. We don't think that we should just waive those rules for someone else just because they happen to have a similar skin color. So there are a lot of Latino voters who believe in the rule of law and think we should, you know, rebuild the rule of law in immigration.

KOBACHAnd then the other thing I would point out about, you know, the political question you asked is independent voters, when polled, are very much in favor of the Arizona law. In fact, there was a poll -- Quinnipiac poll that came out just a couple of days ago, and it showed that looking at the entire electorate, 68 percent are in favor of the Arizona law. So I don't think this is going to hurt Republicans above all.

PAGEAnd, Mr. Kobach, I've heard conflicting things about whether you're an advisor to the Romney campaign. Are you, in fact, an advisor to the Romney campaign?

KOBACHI guess the best term would be informal advisor. I don't get paid. I don't have a title, but I do communicate regularly with the campaign.

PAGEOK. Kris Kobach, the secretary of state from Kansas, my home state. Thank you so much for joining us.

KOBACHMy pleasure.

PAGENow, let me give the panel a chance to respond to what we just heard.

KELLEYSure. Well, I'll go. So first of all, in terms of what Latino voters think, Latino decisions that does -- the best polling, I think, of Latino voters has said that this issue is a ticking time bomb with the Latino community, that this -- how the court decides is really a proxy for whether Latinos feel accepted in this country. This is a threshold issue. My family is a Latino family.

KELLEYI can tell you that they are going to be watching very closely what the court says. They listen very carefully to what candidates say about them. And 74 percent of Latino voters in eight states strongly, strongly oppose the Arizona law. So you're talking about something that is very much on the national stage, this transcend state of residence for Latinos, and they do care because you can't tell looking at somebody whether they're carrying the right papers or not.

KELLEYAnd as much as I would love to live in a world that Mr. Kobach and Steve live in, where people aren't racially profiled, that they're not stopped because of how they look or how they dress, that's not the world that we live in. And that's the reason why there's been such vociferous opposition by police because this will make communities less safe, by 44 former state attorney generals that have filed brief, saying, please strike down this law. Scores of state and local cities and towns have also asked that the law be struck down.

KELLEYSo this isn't an esoteric legal argument where we're not going to be going after people of color. This is going to be felt very much like an attack of people of color.

PAGEJonathan.

TURLEYI actually have a column out this morning in USA Today on this. The column looks at the fact that this -- it's an ironic case because we are almost at the 12-year -- later this year, the 12-year anniversary of Bush v. Gore, where the Supreme Court chose the president of the United States. This case could have the makings of that type of case, the convergence of politics and law. Most political commentators have said that the Latino vote could well decide the election, and particularly Florida could decide the election where Latino vote is enormously important.

TURLEYMost of the commentators indicate that Romney has to secure 40 percent of Latino vote, and right now, Obama has 69 percent in polls. He won last time with 67 percent in polls. But the interesting convergence of law and politics on the issue is that what Obama really needs in this case is a loss. The best thing that could happen to Obama would be to have these five conservatives kick him down the road because that would galvanize Latino vote.

TURLEYRomney would be in a box 'cause he would have a hard time, you know, pulling out the Etch-A-Sketch and redoing this because he can't criticize the conservatives on the court. So, privately, I wonder if the president is sitting there just hoping to God he has the worst lawyers in the country.

PAGEYou know, that seem so cynical to me, though, because if that happens and the law stands, a policy -- I mean, he's been rebuked in his interpretation of what's constitutional. And the law stands and all the impact of the law that he's been warning about.

TURLEYWell, you know, this is the -- unfortunately, the terrible thing about the Electoral College is that this campaign is shaping up to be one state, and all of the campaign is focusing on Florida. And even though what Obama's lawyers are saying in court would really tick off most Americans to support higher enforcement levels, it appeals strongly to people in Florida.

PAGEYou know, and when we think about swing states, we'd also include Colorado, Nevada, New Mexico, all states that have big Latino populations. Tamar.

JACOBYYou say how cynical, how awful. Unfortunately, this is what has become of the immigration issue in the past five years. LBJ used to say to his fellow legislators, do you want a bill or an issue? And a bill meant something that people were working on to solve, come into compromises. An issue meant a wedge issue that you went back and used to get votes and raise money at election time.

JACOBYImmigration has been -- has begun from being a bill to an issue steadily downhill for the past five years with both parties: Democrats playing cynically to Latinos, Republicans playing cynically to their base, and almost no one wanting to solve it. That would take away that gold mine that keeps on giving. This is of a piece with that.

PAGESteve, what do you think?

CAMAROTAWell, I think the politics are great for enforcement. As Kris Kobach pointed out, people overwhelmingly in this country favor this law. Where there's opposition, it's generally among elites. You don't find much support for the law among editorial pages. You don't find much support among, say, journalists. You don't find much support on -- for the law amongst, say, the lawyer class in the United States.

CAMAROTABut generally, the American people and voters -- even a large fraction of Latino voters -- support the law, and the reason they do is illegal immigration is an enormous problem in states like Arizona. Despite very caustic and horrific attacks on the state, the law remains very popular among the people of Arizona because the illegal population in Arizona exploded in that state. At the same time, the state is spending something like $2 billion on education for children from illegal alien families.

CAMAROTAOne out of three uninsured people in that state are illegal aliens or their young children. The labor force participation, even before this recession, of young and less educated people -- teenagers, people who only have a high school degree and are in their 20s -- has declined dramatically in that state. So workers and taxpayers rose up and passed what is a popular law.

PAGEI'm Susan Page, and you're listening to "The Diane Rehm Show." We're taking your calls, 1-800-433-8850. Jonathan Turley was just talking about the importance of Florida. Let's go to Miami to take our first caller. Malone is on the air. Hi, Malone.

MALONEHow are you doing, ma'am?

PAGEGood.

MALONEI just wanted to say about the politics of this. You know, prior from doing this conversation or this -- the discussion of this law, you had a lot of people suggesting that -- speaking to the whole profiling thing -- you had a lot of people talking about how Latinos down in that area, they only commit crimes, and they rob and they sell drugs. So we generalize the whole population. We always -- there's also some discussion about women, Latino women who come to this -- to the country, and they drop babies.

MALONEThey grab anybody off the street. They drop babies. And then we had, I think, Sen. Graham suggesting that we revisit the 18th Amendment. I just -- you know, when -- I think people, Latinos, just like -- I'm an African-American. Just like -- when we hear this kind of things, we don't get the idea that we are somehow accepted. So could someone respond to that? Thank you.

PAGEAll right. Malone, thanks so much for your call. Angela.

KELLEYYeah. I think the caller is spot-on. And that is often how Latinos are made to feel, right, that we come here, we just want to have a child, that we get on welfare, that at the same time we steal jobs and that our crime rate is higher than everybody else's. And, you know, it's wrong, wrong and wrong again. But that tends to be -- as, you know, as Tamar was saying, just the debate is so polarized and so emotional, and so you can't have a calm discussion.

KELLEYIt's remarkable to think that just not that many years ago, a comprehensive immigration bill did pass the Senate. Twenty-three Republicans did support it. So it is within our Congress' ability to not make it an issue, but to really get a bill done. And I'm hoping that whatever the Supreme Court does, that it'll be -- it'll send a strong message to other state laws -- lawmakers: First of all, don't pass Arizona, but rather turn to your federal counterparts and tell them to stop hiding and stop screaming and actually get a bill done that would do something with the 11 million who are living here without papers.

PAGEBut, you know, we saw President George W. Bush make a big effort on immigration from the Republican side and failed to get any kind of comprehensive legislation through. I just wonder what the realistic prospects are in this climate for any kind of comprehensive federal bill.

JACOBYWell, you know, I think that's one of the interesting things about state experiments. So, last year, one of the reddest states in the country, Utah, passed a law that had not just enforcement, but also work permits for the unauthorized workers in the state and a guest worker program. If the Supreme Court were to give the states more power to pass a broad array of laws, and states started doing experiments that ended up prodding Congress to act, I don't think the ultimate good goal would be 50 different state policies.

JACOBYBut if you had three, four, 10 states passing bills, some of them constructive, that might get Congress to the point where they did realize, you know, hey, we can do this, too. States are clamoring for a solution. Republicans and some of the states voted some -- for some hard bills. Congress could do -- could then do it as well.

PAGEJonathan Turley, you know, the federal government does often encourage state experimentation on policy. Is it -- are you surprised by the aggressive stance they've taken toward these immigration laws?

TURLEYWell, I'm very surprised. For a long time, I was wondering why the administration was pushing this so much. They went out and rather aggressively sued the individual states. They didn't have to. I -- and I kept on wondering, why are you doing this with the popularity of the enforcement of immigration laws? Then it occurred to me, you know, maybe a few of them actually want to lose this perfect timing, you know, at the end of July, right before the conventions, great timing.

TURLEYThe other thing that's fascinating is the disconnect. If there's one benefit to this fight, it has brought a degree of honesty in the debate. The Obama administration is not the first administration that slow-walked deportation. Most prior administrations never fully enforced in the sense of deportation, but most of them were denied that. And, in fact, the Obama administration for this case sort of followed the same script and said, we're enforcing as much as we can.

TURLEYBut then in the arguments, the administration described Arizona's approach as "maximal attrition through enforcement." And that's a fancy way of saying, we just don't want to deport all the illegals that we find. Half the illegals that are deported every day -- it's about 900 every day -- are convicted of criminal acts. And that's the focus of the administration. They say, we're focusing on dangerous, you know, these dangerous immigrants.

TURLEYBut, of course, the federal law doesn't make that distinction. And so you have this fascinating disconnect, and it comes down to the Electoral College. I think Steve is right. There is great support for tougher immigration laws. And you would think then that the administration would be pursuing the opposite argument. But that's because this election may have come down to one or two states, and we become a nation of Florida.

PAGESteve, I wonder if you have been surprised by how aggressive the federal administration has been in going after the Arizona law.

CAMAROTAI think that the administration has never -- you know, on the one hand, I think, they've never really been the kind of sincere amnesty advocates that folks like Angie and Tamar would like them to be. On the other hand, they have to do something to take care of that wing of the Democratic Party and to satisfy some business interests. And I think this is the way they do it. They throw them this bone.

CAMAROTAThey say, OK, yeah, yeah, we want the amnesty, too. But, you know, quite frankly, it's very unpopular with the American people, so let's move on. So -- but, hey, you know what? We're going to sue the states whenever they try to do anything, and we'll -- we may even have to make some convoluted arguments like, yes, the law is on the books, but we like to ignore it. And therefore it's preempted. So that's what I think they're doing. They're throwing a bone to their base.

PAGEWhen we come back, we'll try to maybe readdress that issue of amnesty, which I don't believe the White House has advocated. And we'll take some of your calls, and we'll also talk about a new Pew Hispanic Center study out today that shows some remarkable changes in Mexican immigration to this country. Stay with us.

PAGEThe lead story this morning in The Washington Post and USA Today is from a Pew Hispanic Center study that shows from immigration -- immigration from Mexico has declined significantly. In fact, it's a net zero. How significant a change is this from what we've seen in the past, Tamar?

JACOBYIt's a very significant change. But there are several different reasons that go into it, and it's very important, which are the reasons. Obviously, the intense enforcement on the border is one of the reasons. Big changes in Mexico are another reason: Demographic changes, people having fewer babies, wages going up in Mexico. But, third, our economy, and we -- and all of those, we don't need the workers in quite the same way. We're not building houses. That was a big part of the draw for immigrants.

JACOBYSo what we don't know is which of these three changes is the most important thing driving this down. And when our economy picks up again, we don't know -- I think we're going to need immigrant workers again. And if they're not coming from Mexico, we're going to be looking to El Salvador and Honduras and further field.

PAGEHere's an email from Daniel, who suggests another reason why me might have seen the change. He says, "Is there proof -- any proof that these laws have had an effect on illegal immigration?" I wonder, Steve, what you think about that.

CAMAROTAAbsolutely. The government estimates that the illegal immigrant population, since it peaked in 2008 in Arizona, is down 34 percent. For the rest of the country, it's about down about 10 percent. So there's very clear evidence. Research by the Public Policy Institute of California as well for the Institute for the Study of Labor have controlled for a lot of factors.

CAMAROTAAnd it shows that the Arizona efforts, both -- especially the earlier law passed in 2007, the employer verification law -- not the one we're talking about so much today -- seems to have had a very big impact. And what's interesting is it doesn't seem to have caused legal immigrants to leave the state -- only illegals. I mean, that's their conclusion.

PAGEAngela, what do you think?

KELLEYYeah, we actually looked into that because we wanted to answer the question, are people going back? And the University of California, San Diego has a program where they interview migrants in Mexico, and then they continue to study them once they're here. And what they have found is that people tend to do two things either in the aftermath of a harsh law. They go deeper underground just to stay away from the police, away from the authorities. Or they go to a friendlier state. They don't actually leave the country.

KELLEYNow, some may be going back. There's certainly a lot of people that are being deported. I mean, Obama deported more people in three years than Bush did in eight. So we've got millions of folks that are being sent back. But I think, in fact, if you look at who the undocumented folks are, this is what we know: Two thirds of them had been here for longer than 10 years. I think the people who are going back are probably people who are more recently arrived, and they don't have roots yet in this country.

KELLEYThere are 16.6 million people, who live with someone who's undocumented. So we've got folks that have been here for a long time. We've got mixed-status families. And I don't think that they're just all going to pack up and go home because, you know what, they are home.

JACOBYSomething else happened in Arizona in the last five years. The housing development market collapsed. It was the biggest housing bust in the country. That's one of the reasons why immigrants are not fleeing or not staying in Arizona. There's no work for them.

PAGEYou know, we've got an email -- actually, a couple emailers who wants Jonathan Turley to revisit a statement he made when you said the Obama administration isn't the first one to slow walk deportation. And these emailers say, isn't it true that deportation levels are really up under President Obama? Do you want -- can you explain what you meant?

TURLEYYeah. There's no question that President Obama has deported more individuals than his predecessor, but it still remains a relatively small fraction. And the administration itself has admitted that it simply does not put a priority on deporting all illegal immigrants, that they want to focus on the dangerous individuals. That's why 50 percent of everyone deported have committed crimes. And there you have this sharp divide, where you have folks in Arizona, saying, look, the federal law says that if you're illegal, you have to be deported.

TURLEYThat's the general thrust of it. The American people tend to support that view. And you have the administration saying, yeah, well, laws have to be enforced, and we want to have priorities. And they sort of portray this maximum enforcement approach as naive. And so I think that that is very much like their predecessors. The numbers are up, but it's clear that no administration, in relatively recent years, has gone for a maximum enforcement through deportation, in my view.

PAGESteve.

CAMAROTAWell, let me say this as the demographer on the panel: Pew's research confirms some stuff that we've put out, and that is that it does appear that a lot more people are going home, particularly illegal immigrants, even longtime residents. But Angie is right about one thing. Research by Wayne Cornelius in San Diego suggested that's not the case. So there is a debate among demographers. Like lawyers, they can never always agree on everything either.

CAMAROTABut I think the preponderance of the evidence -- Pew is estimating that out-migration, return migration to Mexico is double what it had been about 10 years ago over the last five years. In my own research, that's exactly the conclusion I've come to. So it does seem that the evidence -- the Mexican census shows it. U.S. Census Bureau data seems to show it. But there is always a debate about these things. But the evidence seems pretty clear that a lot more folks are going home, and a lot fewer folks are coming.

PAGELet's go back to the phones. We'll go first to Suffolk County, N.Y. and talk to Tom. Tom, thanks for joining us on "The Diane Rehm Show."

TOMHi, how you doing? I just wanted to make a comment that, you know, say, you have these laws, New York State drunk driving laws. And I don't understand why any law, whether it's a federal law or a local law -- it's a law so it should be enforced. I don't see what all the talk is about. If there's a federal law saying that in order to be in the United States he has to be here legally, you have to go by certain, you know, get certain paperwork and things like that, I don't understand what the argument is. And I'll just listen to any comments off the air. Thank you.

PAGEOK, Tom. Thanks for your call. So that seems pretty straightforward. Angela, what do you think?

KELLEYYeah. And, in fact, look, our laws are being vigorously enforced. President Obama has put his foot on the enforcement gas pedal from the day he took office, and he's not let up. The prioritization of who is being deported, that's law enforcement 101 principles. You go after the people who have criminal records. You go after the people who pose the biggest threat. You don't go after the people who are jaywalkers. So I think the administration is making sensible choices.

KELLEYAnd they're also, frankly, as I've said, deporting more people than under the Bush administration, under any previous administration. And we have a border that is also more secure. So, to that extent, our enforcement policies are very vigorous. But what isn't working -- and this is why we're having the debate about the Arizona law -- is what do we do about the folks who are already here because they've been here for a long time, because they have U.S. citizen children, because you can't tell, looking at them, whether they're here illegally or not.

KELLEYAnd that's where the demographic changes in this country. Are we just running smack on a collision course with these laws? They don't solve the problem. And as much as the state of Arizona might want to deport illegal immigrants, it can't.

PAGEJonathan.

TURLEYWell, I think that's actually one the more clever aspects of the Arizona law. Many of these other laws impose additional requirements on top of the federal requirements. The Arizona law was really crafted to enforce at the extent -- people like Mr. Kobach were quite clever. But I think that the really central issue here is whether the federal government is talking good game. There's plenty of federal laws that make aspirational statements that, in application, prove to be less than true.

TURLEYI'm not so sure the Supreme Court is going to pull these irons out of the fire for the administration. I mean, I think that the Supreme Court is going to look at a law that says, if you're here illegally, you have to go. And, you know, you have a state saying, we'll help you out. OK, if you're having administrative problems, we've got a lot of people here top help you out. You know what, there's only so much water these justices will carry for Congress.

TURLEYI think that many of them are going to start out saying, you know what, if you don't really want to deport every illegal you find, then put it in the law, you know, maybe open about it. There's a concept in law called perfecting democracy. It's when judges do things to make the democratic process work better. And some of the justices may look at this as perfecting democracy to say, look, if you want to do this, you know, Oliver Wendell Holmes said, if you want to go to hell, I'll gladly send you there.

TURLEYYou just have to be clear about where you want to go. And I think the justices are going to say, hey, if you want to adopt this as a policy, be open about it 'cause we're not going to do it through implied interpretation.

PAGEGo ahead, Steve.

CAMAROTAWell, just very briefly, the other thing is is that what this new research is confirming is what a lot of pro-enforcement people had believed. People are not always permanently anchored here. Some illegal aliens might never go home. But we do know that the argument that had been made that, look, once here, they're permanently here. There's no way they're going home. Yeah, maybe fewer people will come. That appears not to be the case in Arizona and nationally.

CAMAROTAThese few numbers, my own research, stuff DHS has put out, people do go home, and that's really one of the key thinking behind the Arizona law, just like when a policeman pulls one person over on the highway for speeding. I know I slow down. It changes behavior. If you make enforcement a real possibility, it changes behavior. And one of the things that these kinds of laws were designed to do is encourage return migration so folks go home.

PAGEWe're getting a lot of emails from people with personal stories. Here is one from Matt in Texas. He writes, "As long as the GOP uses race to divide Americans, it continues to be a boon for the Democrats. I am Latino, and I'm socially conservative, but I will not vote for a GOP candidate due to their stand on this issue. The rest of my extended family feels the same way." Let's go to Maurice. He's calling from Rockville -- Rockford, Ill. Maurice, hi.

MAURICEHi. How are you?

PAGEGood.

MAURICEIf these laws are supposed to bespeak a common sense and identification, why have employers been ignoring them for years and years and years during hiring practices?

PAGEAll right. Maurice, thanks for your call.

JACOBYI mean, the point about immigration is that the laws have been so unrealistic in relation to our labor needs. So we -- people -- farmers need people to pick the lettuce. Americans are getting more and more educated. They don't want to pick lettuce any more. Hotels, seasonal resorts in towns where there are no Americans can't find enough Americans even in the downturn to do the work. And certainly, during the boom and even now, to a degree, in the downturn, we -- immigrants are a critical part of our economy.

JACOBYBut our laws have not admitted enough to supply a legal supply, and that's why there have been two signs of the border: one that says keep out and one that says help wanted. That's the hypocrisy that we -- after 30 years of that hypocrisy, that's why we have 11 million people in the country that we don't know what to do about. And that's why enforcement alone and driving them out is not going to be the answer.

JACOBYWe're still going to need to deal with the 11 million people who are -- at least 10 million people, or even 9 million people after a lot of them go home, who don't go home and who are left here and the products of that hypocrisy that we have to face up to. And when the economy picks up, we're going to have a continuing labor need. That's why just deporting them or encouraging them to self-deport is not the answer.

JACOBYThere needs to be a more robust answer, three-dimensional answer. Whether it comes from Congress or the states, we need a three-dimensional answer instead of the one-dimensional answer of the Arizona law.

PAGEAnd, Steve, it's certainly the case that we've heard from farmers and ranchers and small entrepreneurs who depend on immigrant labor, that they're very concerned about these laws. In some cases, business owners and farmers who are themselves quite conservative worry about the impact that this had on their livelihood.

CAMAROTAWell, here's the thing. About 5 percent of all illegal immigrants work in agriculture. So when we think about illegal area -- labor in the United States, the agriculture question is almost irrelevant. And one of the things that makes it even more irrelevant is we have an unlimited program that works pretty well, H2A, that lets best workers comes in specifically for agriculture. But right now in America, we're pushing about 30 million less educated people.

CAMAROTAThat's people who have no education beyond high school and are adults, 18 to 65, not working. Labor force participation is the lowest it's been in generations for the less educated. Wages have declined 22 percent for the least educated in the United States. If it's true that employers have a problem, it's 'cause wages are so low.

PAGEI'm Susan Page, and you're listening to "The Diane Rehm Show." We've gotten a tweet from Randy. He writes, "I live in Florida. This state would dry up and blow away without illegals to work here." Let's go to Swoope, Va., and talk to Emmanuel. Hi, Emmanuel.

EMMANUELHi. I just wanted to say that I grew up in Southern California. My father was an illegal. My mother was also Hispanic. And I used to be stopped by the police very frequently. And I came to accept it as a fact of life. And I think, as I'm an old man now, I think it's a safety precaution, and I don't mind it. And I don't know what people carrying on about it. Is it some -- really, the police used to stop me all the time. Now, I'm an old man.

EMMANUELI've got a long beard, and people don't think of me as being as Hispanic now. But it's easy. I don't know why we're making such a fuss about it, especially in an international scene where we've got all kinds of people coming in the country who look like Chicanos. And we have to be able to discriminate. It's important.

PAGEAll right. Emmanuel, thank you so much for calling and offering us your perspective intellect. Angela?

KELLEYYeah. It makes me sad that he has had to endure so many obvious decades of being singled out by how he looked, that he's now just come to accept that. You know, look, I'm the mother of two kids, and I don't want my kids to ever, ever say that. So this country is built on a fundamental principle that we judge people by their character, not by the color of their skin.

KELLEYAnd the problem with these laws is it's taking us backwards, not forwards. It hurts state economies. It hurts the people who live in the states. And, you know, at the end of the day, this is a federal question. It is not one that 50 different states can decide on their own.

PAGEThe Senate is going to have a hearing today about this Arizona legislation. And Chuck Schumer, the New York senator, says -- indicates in a story this morning in The Washington Post that Senate Democrats plans to force a floor vote on legislation that would invalidate Arizona's immigration issue if the Supreme Court upholds the law this summer. Now, it's unlikely this legislation will get through Congress, which has great difficulty doing most anything. But, Jonathan Turley, is it possible for Congress to do this? Could Congress take the step?

TURLEYWell, it could. You know, it could simply do an express preemption provision that preempts state law. In many ways, today's move shows the Democrats doubling down, which is the subject of my column this morning, which is that this is a good issue for Obama and the Democrats. It's a perfect wedge issue. It'll be even better if they lose in front of the Supreme Court. But it'll be interesting to see how this plays out.

TURLEYIt's based on the theory that with women going heavily for Obama and with the black vote going heavily for Obama, it comes down to Latinos and whether they can push Romney below 40 percent on that vote. Right now, Obama is as popular with Latinos as he was when he was elected. And this is going to reaffirm that. The question is that there's assumption that they will not have a displacement effect on other states.

TURLEYAs Steve has noted, this is -- remains very popular in many of these other states and whether it could undermine a couple of states that are currently in the Obama category. So it's a delicate balance, and it's sort of taking on this sort of game of chicken between the Democrats and Republicans. Someone's going to be right, and someone's going to go over the cliff.

PAGETamar, tell us, where does Mitt Romney stand on the Arizona legislation?

JACOBYMitt Romney has been a little equivocal on the Arizona legislation. He made one remark some months ago where he said he thought it was a good thing and other states should follow it. Then there was a remark last week where he said he wasn't talking about this law. He was talking about another law. Romney is a work in progress on immigration. And I hope -- and he started to say things about, well, we do need illegal workers. So that was -- that's the remark yesterday.

JACOBYHe's starting to realize, well, maybe, you know, he's against -- he's strongly against illegal immigration, but maybe we do need legal immigration. And we need to fix those programs. You know, what I hope for the Republicans -- I am a Republican. You know, I think that Latinos, like everybody else, their first issue was the economy. Their second issue is the economy. Their third issue is the economy, and then maybe it becomes education. Obviously, immigration is a threshold issue for Latinos.

JACOBYIf you diss people, they -- in the first thing you say, they can't hear what you say after that. And, right now, that's, unfortunately, Romney's problem. He's like a salesman who comes to your door and the first he says is I don't like people like you. And then he tries to sell you something. If he can get over that threshold, neutralize some of the bad things he said about immigration, I think Latinos could hear him on a lot of other issues.

PAGETamar Jacoby. And we've also been joined this hour by Steven Camarota, Jonathan Turley and Angela Kelley. Thank you all for being with us on "The Diane Rehm Show."

TURLEYThank you.

CAMAROTAThank you.

KELLEYThank you very much.

PAGEI'm Susan Page of USA Today, sitting in for Diane Rehm. Thanks for listening.

ANNOUNCER"The Diane Rehm Show" is produced by Sandra Pinkard, Nancy Robertson, Denise Couture, Monique Nazareth, Nikki Jecks, Susan Nabors and Lisa Dunn, and the engineer is Tobey Schreiner. A.C. Valdez answers the phones. Visit drshow.org for audio archives, transcripts, podcasts and CD sales. Call 202-885-1200 for more information. Our email address is drshow@wamu.org, and we're on Facebook and Twitter. This program comes to you from American University in Washington. This is NPR.