This, I think is the ad that did Senator Specter in (I mean, if an ad can really do that):
It's the way Specter said "re-elected". Really. That's what I think it came down to. It was very close, but in the end, possibly a touch of anti-incumbent feeling but also another opportunity to vote against Specter brought out more Sestak voters. But I'm sure a number of people in the voting booth just thought "Guess who's not getting re-elected."