Edwards & Obama v. The Rest of the Field

An interesting dynamic has emerged in this debate. On one side are Edwards and Obama. On the other are Clinton, Biden and Dodd.

Clinton, so far, has been spared having to attack either Obama or Edwards because Dodd and Biden are handling that task nicely. Biden just took a personal and direct shot at Edwards for his insistence that voters should look at the candidate who has walked the walk.

"It's not where you've been in the last two years, it's where you were in the six years in the Senate," said Biden. Zing!

Minutes earlier Clinton said she and Dodd had worked together to protect mine workers but that the Bush administration had blocked their legislation.

Those are just the two most recent examples of the factions emerging tonight and perhaps in the race more generally. It's one to watch.