Who is Perry going to lose Iowa to? Bachmann, whose campaign is dead? Gingrich, who never had a campaign in the first place? Romney, who's basically ignoring the state? Perry was never going to win New Hampshire. And if he wins Iowa, he wins South Carolina.
If Romney's campaign stops emphasizing that they're not trying to win in Iowa, Romney can win in Iowa. Iowa is more unsettled than the national race - a Cain or Bachmann victory seems unlikely, but it wouldn't be surprising. (Should I count out Santorum? Yeah, I probably should.)
