The Times' proof? None, really. The Times just knows.
Just like on Tuesday, after the AIG bonus story broke, the Washington Post just knew that "the public" was furious with the White House (not at corporate greed), and that Obama's entire agenda was in danger of collapsing over the AIG story.
What proof did the Post offer to back up that sweeping claim? What independent experts confirmed the claim and what poll results bolstered it? None. In fact, I have not seen a single new poll that offers any insight into how much blame the White House gets for the AIG story or if Obama's approval rating have taken a hit.
But the press doesn't bother waiting. Even when announcing how "the public" is reacting to a news story, the press doesn't actually really care what "the public" thinks. The press decided immediately that the AIG story was a "cataclysmic" event for Obama and that "the public" was blaming him.
I suppose it's just a coincidence that the RNC thinks the exact same thing.