It's still anyone's game.
The latest poll shows Mitt Romney and Ron Paul leading the field in a virtual dead heat.
But surging in the polls is former U.S. Senator and former Illinois resident Rick Santorum.
"What we're seeing here is a lot of momentum and intensity," Santorum said. "And if we can finish in the top three, that's a good finish for us"
Santorum's so-called "surge" could not have happened at a better time.
In Polk City, Iowa Monday morning, he talked about spending his senior year at Carmel High School in north suburban Mundelein and appealed to his former classmates.
"All the Carmelites, Carmel folks, the Corsairs, help us out," he said.
Romney sounded confident. An Iowa win Tuesday, even with a small plurality, would be the perfect set up for a decisive regional victory in New Hampshire on Jan. 10.
"We're going to win this thing with all of our passion and strength and do everything we can to get this campaign on the right track," Romney said.
Meanwhile, Paul said he would be disappointed not to finish first or second.
"When we travel around and see the enthusiasm, we think they're gonna show up," Paul said.
Running behind in the latest pre-caucus poll, candidates Rick Perry and Michelle Bachman could be forced out of the race by a fifth- or sixth-place finish that could affect their fundraising.
"We've already bought and paid for our tickets to South Carolina," Bachman said. "So, we're on our way."
In Independence, former house speaker Newt Gingrich, who led the Iowa poll in late November, now doubts he can win the caucuses. He blamed negative television ads by other candidates:
"Iowa has a chance to send a signal that we are sick of negative ads, candidates that ran negative ads," Gingrich said.
Meanwhile, hundreds of workers for the various campaigns have arrived in Iowa. Doug Bennett drove from Deerfield, Ill., to work for Perry.
"You always try to pick the best candidate and they're all not going to be perfect on both sides," Bennett said. "So everybody has to make the best choices possible."
Ron Paul was joined by his son, Sen. Rand Paul, during his final full day of campaigning.
And Romney, the former Massachusetts governor, continued his attacks on President Barack Obama:
"We haven't had a president see this many jobs lost during their term since Herbert Hoover," Romney said. "This is just an American Tragedy."
But Chicagoan Mike Smith, a Democrat, arrived in Iowa Sunday night to work a phone bank on behalf of the president. He and other Obama re-election supporters are trying to match the Republican intensity.
"By us being active and doing what we do, we're taking away some of the media attention that they're getting and that's what we should do," Smith said.