Nate Silver outlines scenarios:
If a populist candidate like Sarah Palin won in Iowa and Mr. Romney finished a strong second, that might not be so bad for him: he’d have a good opportunity to recover in New Hampshire, eventually setting up a conservative-versus-moderate “play-off” in the later states. But if Mr. Romney were to be overtaken in Iowa by a candidate like Tim Pawlenty or Mitch Daniels — someone who had a plausible chance of winning in New Hampshire as well — he’d be in a great deal of trouble.
The Dish 