I just noted that Obama may have been hurt by Edwards's inability to draw more votes from Hillary today. One thing that has to concern the Obama campaign going forward is whether Edwards's loss in Nevada is so crushing--it looks like the final margin is going to be something like 50 to 45 to 5 for Edwards--that the bottom falls out for him in South Carolina, too. Obviously, Obama would prefer to have Edwards alive and strong in South Carolina, siphoning white votes from Hillary.
Another thing to keep in mind, courtesy of today's entrance polls: About two-thirds of Nevada caucusgoers said Tuesday night's debate was very important. Hillary won those people by a 54-33 margin. I don't think we can pin that entirely, or even mostly, on Obama's "greatest weakness" response, but it might have played some role. Maybe voters really aren't up for candor when it comes to these things, which is a little depressing. (Or, as I suggested earlier, maybe too many people thought Obama was saying he was a weak manager, when he was actually copping to being personally disorganized.)
--Noam Scheiber