Yesterday I ran into a well-known Democratic activist who pays close attention to the ad wars. I told him my theory that while the media obsesses over convention stagecraft the election is being defined for voters in critical swing states by those 527 attack ads linking Obama to Bill Ayers and thus--ludicrously--to 9/11. He scoffed. His research, he told me, showed that the ad buy has been overblown, so far totalling less than $500,000. So maybe this concern is overstated. On the other hand, summer's not even over yet and I'm sure we can expect plenty more of this stuff. The sponsor of the ads, after all, is a billionaire, so there's plenty more where that came from.