In 1969, untreated industrial waste burst into flames on Cleveland’s Cuyahoga river. It ignited not just the river, but a burgeoning environmental movement. The following year, President Nixon established the Environmental Protection Agency. Twenty years later with similar bipartisan support, America’s environmental laws were strengthened even more through far-reaching amendments to the Clean Air Act. Now, that kind of broad political backing for the EPA and its mission seems to have all but dried up. As part of our Environmental Outlook series we discuss why the agency and its mission have become so politicized.