What I love about Ed Rendell is not just that he's constantly off-message, but that he's off-message in constantly changing ways. Last month the Pennsylvania governor and Hillary supporter implied that a black candidate would start off at a five-point disadvantage in his state because "there are some whites who are probably not ready to vote for an African-American." Yesterday he argued, contra the Clinton campaign, that Obama would have a pretty good shot at beating McCain in Pennsylvania.
Now, I'm not saying these two observations are contradictory. But, given how close Pennsylvania's likely to be in the general, it seems like an automatic five-point disadvantage there would really crimp your chances against a formidable Republican opponent. Anyway, I'll bet the Clinton people weren't expecting Rendell to be the one who debunked this particular argument of theirs.
(On the other hand, I could see the governor of Pennsylvania not wanting Obama to write off his state if he's the nominee...)
Update: Here's the video, courtesy of the Obama campaign, of course.