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.

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...