Candidates hone message and hunt voters in Iowa

PERRY, Iowa (Reuters) - White House hopefuls honed their closing messages and targeted undecided voters in Iowa on Monday, three days before the state opens the presidential nominating battle in a too-close-to-call race.

Candidates rolled across the snowy back roads of Iowa to drum up support, while campaigns prepared to unleash a mammoth effort to find voters and get them to participate in the state's caucuses on Thursday.

"If you will stand with me on January 3 and caucus with me, we can change the world," Illinois Sen. Barack Obama, locked in a three-way tussle among Democrats with Hillary Clinton and John Edwards, told a crowd in Perry in central Iowa.

Polls show Iowa races in both parties are too close to call.

A Reuters/C-SPAN/Zogby poll gave New York Sen. Clinton, a former first lady who would be the first woman U.S. president, a four-point lead among Democrats over Obama and former North Carolina Sen. Edwards, who were tied for second.

Among Republicans, former Arkansas Gov. Mike Huckabee narrowly led former Massachusetts Gov. Mitt Romney by two points.

Iowa kicks off the state-by-state battle to choose candidates in the November presidential election. The Democratic caucuses -- in which people gather in groups in locations around the state to show support for their choices -- begin at 6:30 p.m. CST/0030 GMT and the Republicans start 30 minutes later. Results will begin appearing within a few hours.

All of the top Democrats argued that they would be the most electable in the November 2008 election, while Republicans Huckabee and Romney battled over their records as governor.

"If we're serious about winning this election we cannot live in fear of losing it. We've got to think big to be bold," Obama said in Perry.

Polls showed many Iowans in both parties were undecided or open to changing their minds. A Democratic caucus rule allowing supporters of candidates who fail to gather 15 percent of support in a given precinct to switch to another candidate increased the uncertainty.

'FLUID RACE'

"There is a remarkable amount of fluidity in this race right now and a lot of undecideds," David Plouffe, Obama's campaign manager, told reporters.

He said all signs pointed to a large Democratic turnout on Thursday, which could be good for Obama and his effort to attract first-time caucus-goers. The record Democratic turnout in 2004 was just more than 120,000.

"We think as turnout increases we have a much better opportunity to profit," Plouffe said.

Republican Romney has spent the last few days airing ads attacking his chief rivals -- Huckabee in Iowa and Arizona Sen. John McCain in New Hampshire, which votes five days after Iowa.

Huckabee, a Baptist minister, has fired back with questions about Romney's honesty, suitability for the White House and his own record as governor.

After producing some new attack ads of his own, Huckabee said later he had paid for them but decided not to run them because he wanted to maintain a positive campaign.

"I just feel that we need to change the tone of the debate," he told reporters.

Earlier, bundled against the cold in a bright yellow running jacket, Huckabee took an early morning run around a Des Moines lake with a few supporters.

Asked who would win if he raced Romney, he took a jab at Romney's recent conversion to an abortion rights opponent. "Of course he'll be running both ways the whole time," Huckabee said.

At a news conference in Bellevue, Iowa, Romney criticized Huckabee for granting a number of pardons in an arbitary manner.

He said he would set up guidelines to handle pardons and defended his own decision as governor to deny a pardon to an Iraq war veteran who had sought to overturn an assault conviction for shooting someone with a BB gun when he was 13. Huckabee has criticized the decision.

"My desire was to make sure that I erred on the side of protecting the public, and I guess if I were Governor Huckabee I don't know that I'd be raising the issue of commutations and pardons," Romney said.

On Monday Romney launched a biographical ad stressing his executive experience.

"I've spent my life tackling big problems, helping turn around business, the Olympics and state government," Romney said in the ad. "Together we can grow our economy, stop illegal immigration, defend life and preserve the values that make America the hope of the Earth."

(Additional reporting by Ellen Wulfhorst, Ed Stoddard, Andy Sullivan; writing by John Whitesides; editing by Vicki Allen)

(For more about the U.S. political campaign, visit Reuters "Tales from the Trail: 2008" online at blogs.reuters.com/trail08/)