This is Obama's core message. In one way or another, he says it all the time. It's his kicker on the stump. You cannot watch an interview with the president or one of his subalterns without hearing it.
And yet, I don't think I've ever heard a TV interviewer, host or pundit ask, "What are you talking about?"
Finally, the Washington Post's "fact-checker," Glenn Kessler, (not exactly a darling of the political right) tackled it recently. He found that it's a lie, giving it three "Pinocchios" out of four. He also found that the Obama campaign has virtually no citations to back up the claim. The supporting material for the ad quoted above cites a single column by the Post's liberal blogger, Ezra Klein, who told Kessler: "I am absolutely not saying the Bush tax cuts led to the financial crisis. To my knowledge, there's no evidence of that."
Klein is right. So is Kessler. "It is time for the Obama campaign to retire this talking point," Kessler concluded, "no matter how much it seems to resonate with voters." He would have given it the full four Pinocchios save for the fact that Obama occasionally throws in "deregulation" along with "tax cuts" as part of the explanation. In its defense, the Obama camp says it means all of Bush's policies, not just the tax cuts it harps on almost exclusively -- never mind that even Obama admits Bush issued more regulations than he did.
The question of what caused the crisis is obviously still controversial (though, Kessler notes, the official inquiry makes no mention of Bush's tax cuts). But a consensus seems to be forming around the following narrative: The federal government, out of an abundance of concern for the plight of the poor and middle class, made it too easy to buy a home. Congress, on a bipartisan basis, set unrealistic affordable-housing goals for Fannie Mae and Freddie Mac. President Clinton used those goals to expand access to mortgages to low-income borrowers. Then President George W. Bush, with the approval of Congress, expanded the practice, until way too many low-income or otherwise underqualified Americans owned mortgages they couldn't afford.