The Consumer Financial Protection Bureau has been under assault almost from the moment it was put on the drawing board. The battle lines are familiar. Democrats versus Republicans. Yesterday a GOP-led House subcommittee approved three bills that would change the agency’s structure. Republican critics said the measures would improve the CFPB, partly by making it more transparent. CFPB supporters blasted the bills as an attempt to cripple the bureau, which the banking industry has lobbied hard against. The continuing fight over the new watchdog of banks, credit card companies, the mortgage industry and other consumer lenders.