DES MOINES, Iowa (AP) - The White House their goal, Republican presidential hopefuls raced across Iowa on Monday in a final, full day of frenzied appeals for support in precinct caucuses that open the 2012 campaign. "It is the race you make it," an upset-minded Rick Santorum told voters soon to pick a winner.

In the race's final hours, former Massachusetts Gov. Mitt Romney predicted victory and former House Speaker Newt Gingrich all but forecast his own defeat.

From Sioux City in the western part of the state to Davenport in the east, the six presidential hopefuls hustled through 23 fast-paced campaign events combined. That and the $13 million or more already spent on television commercials was evidence enough of the outsized importance Iowa holds in the race to pick a Republican opponent for President Barack Obama next fall.

Romney had one eye on his GOP rivals and another on Obama as he argued he is in the best position of all to capture the White House. The president has been "a great divider, the great complainer, the great excuse giver, the great blamer," said the former Massachusetts governor, who is making his second try for the nomination and has been at or near the top of the Iowa polls since the campaign began.

Later, before a noisy crowd in Marion, he predicted his own victory in a state that humbled him four years ago. "We're going to win this thing with all of our passion and strength," he said.

Texas Rep. Ron Paul flew into the state accompanied by his son, Kentucky Sen. Rand Paul, and urged supporters to "send a message tomorrow night that echoes not just around Iowa but ... around the world." Many in the audience of about 300 chanted "end the Fed," a reference to the Texan's pledge to abolish the nation's central bank as a first step toward repairing the economy.

Most polls in recent days have put Romney and Paul atop the field in Iowa, with Santorum in third and gaining ground. More than a third of all potential caucus-goers say they could yet change their minds.

"Do not settle for less than what America needs to transform this country. Moderate candidates who try to appeal to moderates end up losing," Santorum, the former Pennsylvania senator, said in a slap at Romney.

After absorbing a pounding in television commercials from Romney's deep-pocketed allies, Gingrich said he was looking ahead to next week's primary in New Hampshire, and then to one in South Carolina on Jan. 21

"I don't think I'm going to win, I think when you look at the numbers that volume of negativity has done its damage," he said of the Iowa caucuses.

Romney is viewed as the overwhelming favorite in New Hampshire, although Santorum, Paul and Gingrich have all said they intend to campaign there.

South Carolina figures to be more wide-open, the first contest in the South, and in a deeply Republican state.