This op-ed from Bloomberg on why the failure of the Fannie/Freddie reform bill in 2005 was the turning point:
Now that the collapse has occurred, the roadblock built by Senate Democrats in 2005 is unforgivable. Many who opposed the bill doubtlessly did so for honorable reasons. Fannie and Freddie provided mounds of materials defending their practices. Perhaps some found their propaganda convincing.
But we now know that many of the senators who protected Fannie and Freddie, including Barack Obama, Hillary Clinton and Christopher Dodd, have received mind-boggling levels of financial support from them over the years.
Throughout his political career, Obama has gotten more than $125,000 in campaign contributions from employees and political action committees of Fannie Mae and Freddie Mac, second only to Dodd, the Senate Banking Committee chairman, who received more than $165,000.
Clinton, the 12th-ranked recipient of Fannie and Freddie PAC and employee contributions, has received more than $75,000 from the two enterprises and their employees. The private profit found its way back to the senators who killed the fix.
There has been a lot of talk about who is to blame for this crisis. A look back at the story of 2005 makes the answer pretty clear.
Oh, and there is one little footnote to the story that's worth keeping in mind while Democrats point fingers between now and Nov. 4: Senator John McCain was one of the three cosponsors of S.190, the bill that would have averted this mess.