From your own post:
Fannie Mae, the nation's biggest underwriter of home mortgages, has been under increasing pressure from the Clinton Administration to expand mortgage loans among low and moderate income people and felt pressure from stock holders to maintain its phenomenal growth in profits. In addition, banks, thrift institutions and mortgage companies have been pressing Fannie Mae to help them make more loans to so-called subprime borrowers... In moving, even tentatively, into this new area of lending, Fannie Mae is taking on significantly more risk, which may not pose any difficulties during flush economic times. But the government-subsidized corporation may run into trouble in an economic downturn, prompting a government rescue similar to that of the savings and loan industry in the 1980s.
In the early and mid-2000s (decade), the Bush administration called numerous times for investigation into the safety and soundness of the GSEs and their swelling portfolio of subprime mortgages. On September 10, 2003 the House Financial Services Committee held a hearing at the urging of the administration to assess safety and soundness issues and to review a recent report by the Office of Federal Housing Enterprise Oversight (OFHEO) that had uncovered accounting discrepancies within the two entities. The hearings never resulted in new legislation or formal investigation of Fannie Mae and Freddie Mac, as many of the committee members refused to accept the report and instead rebuked OFHEO for their attempt at regulation. Some believe this was an early warning to the systemic risk that the growing market in subprime mortgages posed to the U.S. financial system that went unheeded.
The reality is that the CRA got the ball rolling in the mid 90's. Wall Street in their attempt to mitigate the risks from the CRA's mandated created a product that packaged those loans in to CMO's and Credit Risk Derivitives and got them off the books. Once they created those products out of necessity due to the Government mandate to accept sub prime borrowers they realized how profitable that business could be and away we go.
Plenty of blame to go around on this thing for sure. That said when the Bush administration raised the warning flag in testimony to Congress they were shouted down by the likes of Barney Frank and Chuckie Schumer.