The press turns on Obama. It was always going to happen. Would have been better to happen next week - because you never want to be on the defensive like this before major primaries. But it's a good thing for the candidate and the country to keep the heat on all of them. The NAFTA thing, while pretty trivial in the grand scheme of things, is a perfectly legitimate story, and reveals a certain naivete on the art of Golsbee.
As in: why have you still not released your tax returns, Mrs Clinton? After all these years, one candidate remains unvetted. Or do they not want the voters of Ohio to realize just how fabulously rich the Clintons have become?