As with the Obama-McCain debate last Friday, the vast majority of the insta-polls went to the Democratic ticket. Biden won the CBS poll of undecideds 46-21, and the CNN poll of debate watchers 51-36. Independents in the large MediaCurves focus group panel went for Biden about 2:1.

The internals, however, weren't nearly as bad for Palin as the topline results. She got a jump in preparedness in the CBS poll, and the CNN found that a large majority of voters concluded that she had beaten their expectations.

Palin's largest problem, to my eyes, is that she was tangibly nervous for most of the debate, rushing through talking points and canned jokes alike with unsually little inflection. I doubt that this will impact her favorables much -- in fact, it seems likely that her favroables will improve. But it may contribute to the increasing feelings of dis-ease that some voters have with the McCain campaign, which no longer seems like the manifestly safer choice.

--Nate Silver