Joe Klein studies recent polling:
[M]ost of the polls taken since the debate show Gingrich wiping out Romney’s lead in South Carolina, and the campaign in a dead heat. Romney, meanwhile, seems in panic mode, making mistake after mistake–and all the mistakes lead back to one source: his wealth. A good friend of mine who is a political consultant says, "No one ever wins a nomination without a near-death experience." This may be Romney’s.
Josh Marshall provides the above chart:
[W]hat happens when the seemingly unstoppable force of the Gingrich surge collides head on with his second ex-wife (the one he left for his current wife Callista) finally goes public with these kinds of stories tonight just before midnight? And remember, there’s another debate tonight too.
Nate Silver, meanwhile, warns that Perry's voters won't necessarily move to Gingrich.
The Dish 