Regarding the Zogby poll Mike referenced below, I think the most interesting part is at the bottom of the article. Check out this chart of potential general election matchups:

Giuliani 47%, Clinton 40%	Giuliani 40%, Obama 46%	Giuliani 46%, Edwards 40%
McCain 47%, Clinton 39%	McCain 40%, Obama 44%	McCain 47%, Edwards 38%
Romney 35%, Clinton 45%	Romney 29%, Obama 51%	Romney 32%, Edwards 47%

Right now Romney would lose badly to any Democrat. But the really interesting thing is that McCain and Giuliani are leading comfortably over both John Edwards and Hillary Clinton, while Barack Obama is beating both. He's running 12-13 points better than either Edwards or Clinton in a general election trial heat matchup. As it stands that would be the difference between losing and winning. Now, trial heat matchups this early are of limited value, but they do say something. Right now there are a lot of swing voters who like Obama but don't like Clinton or Edwards. (Of course, this could very easily change over the next 20 months.) I wonder if Obama or his supporters will start using the electability argument. --Jonathan Chait