Chris makes a great point about the unique (and uniquely unfair) burden facing Obama--the need to avoid coming off as an angry black man, which would be death in a presidential campaign. I had a similar thought watching the debate Wednesday night, when Obama seemed to go out of his way to sound circumspect and responsible. On Iraq, for example, he kept reminding us that the military says we can't withdraw more than a brigade or two a month, however much we'd like to pull out immediately. But I think Obama's challenge is even tricker than Chris suggests: Not only does Obama have the burden of demonstrating his electability, but, precisely because he's black, the electability argument alone can't win him the nomination: However electable Obama looks, most primary voters will probably still wonder whether a black man is really that electable. So, for Obama, electability is a necessary but not sufficient condition for winning the nomination. Whereas, for a Southern white guy like Edwards, it may be actually a sufficient condition. The question is: When does the Obama camp decide it has met the electability threshold so it can pivot to taking on Hillary? (Is it even a threshold kind of question?) It's a hugely difficult decision which I don't envy them at all. P.S. The last post I did on this subject elicited a lot of comments and e-mails to the effect of: It may be necessary in theory for Obama to attack Hillary, but it's not really in his nature to do it. And, if it's not in your nature, it would be a huge mistake, since you can't try to be something you're not. I agree. It would be a disaster for Obama to model himself after, say, Howard Dean circa spring 2003. But Obama doesn't need to be an angry attack-dog. He just needs to draw some explicit distinctions, which I'm confident he can pull off in his preternaturally charming way. --Noam Scheiber