Measured by national polling, media attention and millions in the bank, the Republican field appears to have come down to a bout between two heavyweights: Mitt Romney, the former Massachusetts governor, vs. Gov. Rick Perry of Texas.
But in the state where the first nominating votes will actually be counted, the field resembles more of an all-out brawl, with candidates who rank deep on the undercard nationally given a chance to steal an upset finish at or near the top in the Iowa caucuses, the first nominating contest, which will probably be held in less than three months.
“I think it’s a wide-open race,” said Gov. Terry E. Branstad, a Republican. “Michele Bachmann is going to make a very strong effort here. Rick Santorum has put in a lot of effort. Ron Paul — I’ve seen a lot of Ron Paul signs — don’t count him out.”
One main reason is the outsize influence of Christian conservatives, who make up the bulk of the voters in the Republican caucuses. In 2008 they rallied behind the former Arkansas governor Mike Huckabee to give him a surprise victory over Mr. Romney, who spent $10 million and a year on the ground.