| DES MOINES, Iowa
DES MOINES, Iowa Republican White House hopefuls scoured Iowa for undecided voters on Saturday and front-runner Mitt Romney argued that he is the best to take on President Barack Obama as time ran short before the first votes of the 2012 election season.
Iowa Republicans kick off the race on Tuesday to decide who the party will nominate to run against Obama, a Democrat, in November 2012. An unpredictable finish was possible as no candidate had escaped a tight pack battling for the lead.
Polls showed former Massachusetts Governor Romney and congressman Ron Paul in a neck-and-neck fight, with former Senator Rick Santorum and Texas Governor Rick Perry hoping for a late surge and strong showing.
The Des Moines Register newspaper planned to release its highly anticipated last poll on Saturday night that could prove pivotal in picking a winner.
Romney, campaigning in New Hampshire before a final burst of Iowa appearances on the New Year's weekend, kept his focus on Obama's handling of the struggling U.S. economy and foreign policy.
"This president is not a success, this president has been a failure. I don't think he's a bad guy, I just think he's overwhelmed and is in over his head," Romney told a packed event in New Hampshire, site of an important primary on January 10.
Obama, facing a potentially difficult re-election next November, plans to quickly pivot toward politics in 2012 with a heavy travel schedule. A spokesman said Obama will "seize every opportunity he has" to enact policies to help the economy.
"The president is no longer tied to Washington D.C.," spokesman Josh Earnest told reporters in Hawaii, where Obama is spending the Christmas holidays with his family.
IOWA END GAME
Tuesday's Iowa caucuses mark the first of the state-by-state contests that will determine the Republican nominee to challenge Obama. In Iowa's quirky caucuses, voters cast ballots in public meetings after listening to final pitches on behalf of candidates.
In rolling buses and stops in coffee shops and restaurants and even a car museum, Republican candidates campaigned across Iowa cajoling voters to turn out for them at Tuesday's caucuses and trying to raise doubts about their rivals.
Each candidate had a specific goal with the top three or four finishers likely to have enough momentum to continue on to the next contests later in January.
Polls showed as much as 40 percent of the 120,000 people forecast to participate in the caucuses was undecided.
Romney needs to win or have a high finish to give him momentum heading into the New Hampshire primary on January 10. He leads polls in New Hampshire, which borders Massachusetts.
Paul was taking the weekend off in Texas before returning to Iowa on Monday. The congressman, known for his libertarian views, wants to win Iowa to gain credibility and escape an image that his candidacy is a fluke.
Santorum, a former U.S. senator from Pennsylvania with a strong social conservative message, is trying to unite Iowa's influential evangelical Christian voters behind him and score an upset with a surge in the final days.
"A full spectrum conservative, Rick Santorum is rock solid on values issues," a new TV ad run by Santorum's campaign said. "Rick Santorum (is) ... a trusted conservative who gives us the best chance to take back America."
Newt Gingrich is trying to recover from a barrage of negative ads and attacks that catapulted him from the front-runner seat. The former speaker of the House of Representatives got teary-eyed talking about his late mother on Friday and is trying to halt a plunge in the polls.
Gingrich told supporters on Saturday he felt the race is still close.
"I think this is very much in flux. My guess is that a third to half the people who walk into the caucus will potentially change their position or not yet have a position. So this could be a very exciting couple of days," Gingrich told a crowded Tish's Restaurant in Council Bluffs.
Perry is trying to rebound from shaky debate performances that knocked him from the lead and into a fight for third place in Iowa. He told Fox News he was trying to attract "hard-working men and women, God-fearing, freedom-loving Americans."
"I think we're gaining traction every day," Perry said. "I think we're in the race for the top spot."
U.S. congresswoman Michele Bachmann of Minnesota, beset by a series of distractions, was in danger of an early elimination. After winning Iowa's August straw poll -- a key early test of strength among the candidates -- she is limping along at the bottom of the pack.
Political experts said anything could happen, particularly because Democrats and independents have the opportunity to participate in the Republican caucuses, which could give the anti-war Paul a boost.
"The big wild card is how many Democrats are going to come out on January 3 to register their approval of Ron Paul's positions and their disapproval of both parties and the political system in general," said David Perlmutter of the University of Iowa.
(Additional reporting by Ros Krasny and Michelle Nichols in New Hampshire, Jeff Mason and Lindsay Claiborn in Iowa, and Laura MacInnis in Hawaii; Editing by Will Dunham)