This is false. The Community Reinvestment Act, passed in '92 and periodically ratcheted upwards thereafter, forced banks to increase loans to minority groups. It issued guidelines on how lenders should evaluate borrowers for these purposes:
Affirmative-action policies trumped sound business practices. A manual issued by the Federal Reserve Bank of Boston advised mortgage lenders to disregard financial common sense. "Lack of credit history should not be seen as a negative factor," the Fed's guidelines instructed. Lenders were directed to accept welfare payments and unemployment benefits as "valid income sources" to qualify for a mortgage. [1]
While not a regulation issue as such, it's also true that attempts to rein in Freddie Mac and Sallie Mae (semi-governmental entities both) were rebuffed by Congress; even when we knew there was potential trouble, the regulators wouldn't allow market concerns to dictate to their beast.
[1] http://www.boston.com/bostonglobe/editorial_opinion/oped/art... (note this link took forever to come up in my browser)