Updated

Republican presidential candidates are spending their final hours before Tuesday evening's vote pressing the flesh and making one last appeal to Iowa's caucus-goers, who they are counting on to upend the pundits and polling data and offer big surprises on election night.

For Rick Santorum, whose late surge is the timeliest in the twisting and turning race, perseverance is paying off after nearly a year of glad-handing.

"I don't know what the result is going to be, but it's going to be a surprise and a pleasant one for us," Santorum told Fox News on Tuesday, counting on his supporters to go into the 1,700 caucus sites to make a case that he is a viable candidate to go head-to-head with President Obama.

Santorum said he has the essential ingredients headed into the evening's endeavor.

"Caucuses are about enthusiasm and momentum, and we certainly have enthusiasm and momentum," he said.

More On This...

But Michele Bachmann, an Iowa native and the candidate casting herself as the only real conservative in the race, said she has traveled 6,900 miles in the Hawkeye State alone and has the backing of 200 pastors.

"I think we're going to surprise a lot of people here tonight," she said, claiming "soft, hidden support" will reveal itself at the voting sites.

Mitt Romney has been pretty guarded in his predictions so far, though his confidence has shown through, most recently with remarks to supporters expressing confidence that he could take it all the way, starting in Iowa.

"I need every single vote in this room and I need you to get another couple of other votes from your neighborhood and get them to caucus," Romney said. "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 to go across the nation and to pick up other states and to get the ballots I need and the votes I need to become our nominee."

On Tuesday, Romney said he's prepared to take on President Obama.

"We created more jobs in Massachusetts than this president created in this entire country," Romney told Fox News. "We'll be comparing my record with his record, and he comes up very short."

With 80,000 to 120,000 expected to vote Tuesday night, the victor is by no means a shoo-in, having to go to New Hampshire, then South Carolina and then Florida just this month before voting in multiple other races, several held simultaneously in states.

On top of that, Iowa Republicans are still not showing up in the same numbers that they did for Obama in 2008, when 220,000 people went to the caucus sites for the Democratic race. Iowa has gone Democratic in the general election in five of the past six races.

Ron Paul is banking on those factors to propel him forward. Polling nearly at the top, the Texas congressman has been blasted by his competitors as well as the establishment as naive at best, reckless at worst when it comes to foreign policy on Iran.

But Sen. Rand Paul, the congressman's son, said Paul has drawn support from Democrats as well as Republicans inside and outside Iowa, and anyone who discredits that is ignoring reality.

"Right now in the polling, Ron Paul is at or near the top in Iowa. He's solidly second in New Hampshire. If you poll independents -- most people think you need independents to win a general election -- Ron Paul leads all Republicans among independents. If you poll Democrats, Ron Paul leads all Republicans among Democrats. So those are the kind of votes you need. When Reagan won, he pulled a lot of Democratic votes in 1980 and that's how you win," he said.

Iowans, who take their role as political opinion-makers for the rest of the nation, no doubt do shape the future of the race, inasmuch as some of the candidates may not be able to continue past Iowa if they don't present a strong showing.

Anita Perry, wife of candidate Rick Perry, the Texas governor, said she's "a believer" in her husband's race though he will need to double his 11 percentage point polling by Tuesday night to come off as something other than an also-ran.

Perry said what people aren't seeing in news reports are their stops on the campaign trail, where the energy is good, the people are excited and Iowans are taking their role seriously.

Newt Gingrich has bluntly suggested his busted numbers -- he was No. 1 nationally in early December -- are the result of a concerted campaign by Romney supporters to discredit him. But Gingrich, who has conceded he could place third or fourth in Iowa, told supporters late Monday the race isn't over yet.

"When you have 41 percent undecided in the Des Moines Register poll, if each of you in the next 24 hours will talk to every one of your friends, and if each of you would go to the caucus and will make the best possible argument for nominating an experienced conservative with a national record of achieving things, we may pull off one of the great upsets in the history of the Iowa caucuses."

Bachmann, whose schedule Tuesday has her doing interviews on Iowa airwaves and with conservative radio shows nationally, said she is not giving up even if she places dead last on Tuesday.

"We're going to see a lot more changes. It's not over," she said, adding, "we've brought our tickets already for South Carolina. We're going. We're moving forward."