After spending months traversing the state, the Republican presidential candidates are ready for the Iowa caucuses to begin.

Front-runner Mitt Romney is not taking his spot at the top of the polls for granted. He's still fighting and taking aim at his number one target: President Obama.

"I haven't seen such a large gap between promises and performance in a long, long time,” Romney said.

But Romney is also fending off a threat from his own party. Romney and Ron Paul are both trying to shake a last-minute surge by Rick Santorum.

"He's very liberal,” Paul said, "have you looked at his record?"

"All the other candidates just talk about what they're going to do,” said Santorum. “My response to that is that if I had their record, I would talk about what I am going to do too. But I'm actually proud of my record."

The latest Des Moines Register poll puts Newt Gingrich firmly in fourth place, but he’s remaining optimistic about his prospects.

"We may pull off one of the great upsets in the history of the Iowa caucuses, and so I want you to take that attitude into the next 24 hours,” he said.

Two other candidates, Rick Perry and Michele Bachmann, are also banking on an upset.

Noticeably absent from the crowd in Iowa is Jon Huntsman. He's not competing in Iowa, choosing instead to focus on next week's primary in New Hampshire.