Brian pointed out in a comment that Bill Clinton is more responsible than anyone else for the U.S. economic disaster. On his 1992 legislation:

… Fannie and Freddie increase their purchases of mortgages for low-income and medium-income borrowers … Operating under that requirement, Fannie Mae, in particular, was more aggressive and creative in stimulating minority gains. It aimed extensive advertising campaigns at minorities that explain how to buy a home and opened three dozen local offices to encourage lenders to serve these markets. Most importantly, Fannie Mae agreed to buy more loans with very low down payments–or with mortgage payments that represent an unusually high percentage of a buyer’s income. That made banks willing to lend to lower-income families they once might have rejected. …

It does sound like do-gooder Democrats messed with the free market and started this trend:

But did George Bush fix the Clinton mess when he got into office?

… But it was under Bush when the practice began to threaten the economy in a very real way and it was allowed to continue and even encouraged. It was also a mistake to expand the program after 2000 and that is all on Bush’s HUD crew. …

Was Clinton responsible for the Financial Crisis? – Blog for Democracy