This is it.
The Republican presidential candidates will have one last chance on the national stage Thursday night to make their case to voters before the frantic season of caucuses and primaries gets underway. At the Fox News debate in Sioux City, Iowa, everybody but front-runner Newt Gingrich is looking to shake up the race in a big way.
In a primary campaign replete with gaffes and other "oops" moments, the candidates are under pressure to give a steady performance -- they don't want another public misstep hanging in the cold Iowa air for the three remaining weeks before the caucuses. For the middle-of-the-pack candidates, the debate is a chance to demonstrate why caucus-goers should give them a second look. For Gingrich and Mitt Romney, it's a chance to lock down notoriously fickle and straying support.
"This is a clean-up debate," said Steffen Schmidt, political science professor at Iowa State University. "It's sort of the county fair right before the state fair ... where they want to see whether that pony is lame or not."
And minds are not quite made up. "They really are waiting for somebody to close the deal. And nobody has," Schmidt said.
After months of tumult, the polls over the past three weeks have bared a few themes. Gingrich is the unrivaled front-runner. Romney, in second position, can't seem to break through the low 20s. Nobody else is close. But in poll after poll, Romney fares better against President Obama in a general election than Gingrich.
As Romney tries to claw his way back to the top, analysts say the former Massachusetts governor would be wise to stress the electability argument Thursday.
Republican pollster Adam Geller said primary voters are more concerned than usual about whether the GOP nominee can actually beat Obama in November.
"There is an unbelievable reservoir of anger and fear and frustration, and electability does become a very, very important factor in a year like this," he said. "This is one of the reasons why Rick Perry hasn't done well."
He said Gingrich and Romney, with their "grasp of the issues" have done well because they've shown an ability to be competitive against the current occupant of the White House.
To that end, Geller said Gingrich needs to keep his cool Thursday. Though the former House speaker is sure to face attacks from all sides, Gingrich must be "gracious" to his opponents and "have that self-editor fired up," Geller said.
It's a tricky task. Gingrich has pledged to run a "positive" campaign, but Romney is sharpening his attacks. This week, his campaign released a web video that mocked Gingrich for once cutting an ad on climate change with House Democratic Leader Nancy Pelosi. "With friends like Newt, who needs the left?" the ad said.
Romney, who has tried to pigeonhole Gingrich as a Washington insider with little practical economic experience, told Fox News that "people are coming to the conclusion increasingly that I'm the person with the experience and the temperament and the capacity to actually lead America and to defeat President Obama."
Schmidt said Gingrich, while staying positive to the extent he can Thursday night, will have to defend himself. Gingrich's past contract work for Freddie Mac, his one-time support of an individual health care mandate in the early '90s and his proposal to let some illegal immigrants stay in the country have all attracted scrutiny.
But Schmidt said Romney has a tightrope to walk. In dreary times, Romney can't be a downer.
"Mitt Romney has to take on his Republican opponents with a sharper blade and at the same time make people feel that the future is positive," he said.
The other candidates still have a chance to break through. While the national polls show Gingrich and Romney at the top, the Iowa polls have Texas Rep. Ron Paul right up there on the leader board.
In an interview with Fox News, Paul said his loyal supporters could help pull out a victory in the Jan. 3 caucuses.
"We've been working to that end and we've been organizing," Paul said. "We're giving a lot of answers to the questions that so many people across the country are asking."
Schmidt said Minnesota Rep. Michele Bachmann, who won the Iowa Ames Straw Poll over the summer before Perry entered the race and stole her thunder, remains the "sleeper" candidate in the race.
Bachmann, stressing her Iowa roots and advertising an upcoming 99-county Iowa tour, told Fox News that Iowans will realize she's "the one true constitutional conservative" in the race.
"Iowans are going to come back home," she told Fox News.
Perry, too, is trying to regain the confidence of voters. On a bus tour through Iowa, Perry stopped in Council Bluffs Wednesday where he depicted himself as the outsider candidate, and Romney and Gingrich as insiders who are not going to "change a thing."
Former Pennsylvania Sen. Rick Santorum, who has poured his campaign resources into Iowa and was the only candidate to receive a standing ovation at a social issues debate forum in Iowa hosted by Mike Huckabee on Wednesday will attend, as well as former Utah Gov. Jon Huntsman.