Polls show the two former governors running nearly even in Iowa, which will cast the first votes of the 2008 campaign, despite Huckabee's meager resources and the large amounts of time and TV advertising that Romney has lavished on the state. Earlier this month, surveys had Huckabee trailing Romney by double digits.
Huckabee's strong showing, one of the biggest surprises of the presidential race, is threatening the foundation of Romney's candidacy and has shaken up the GOP contest across the country.
On Thursday, Huckabee savored strong reviews for his performance the previous night in the CNN-YouTube debate, at which the former Arkansas governor delivered one-liners, played up his humble roots and proposed abolishing the IRS in favor of a national sales tax.
Romney, by contrast, spent much of the night on the defensive, explaining his former support for legal abortion, dodging the issue of gays in the military and haltingly answering a question about his interpretation of the Bible.
Running third or worse in most national surveys, the former Massachusetts governor has been counting on victories in Iowa's caucuses and the New Hampshire primary five days later to climb past former New York Mayor Rudolph W. Giuliani, the GOP front-runner nationally, and quickly capture the party's nomination.
That remains his hope, and many still see Romney winning Iowa. "He's a good-looking guy, he sounds good, and the people working for him are some of the brightest around," said Ed Failor Jr., executive vice president of Iowans for Tax Relief, one of the state's largest and most influential political organizations. The group has not endorsed a presidential candidate.
But in a sure sign of concern, the Romney camp has begun to raise the prospect of a second-place Iowa finish, insisting it would not hurt his chances in the contests that follow. "It would be nice if Romney won," said Doug Gross, an attorney overseeing Romney's Iowa campaign. "If he finishes in the top two, he's fine."
Others, however, are not so sure. "Romney pretty much has to win Iowa if his strategy is going to work," said David Winston, a GOP pollster who is neutral in the primary. "He's the one with the most to lose."
Dick Dresner, a top Huckabee strategist, put it gleefully: "Everyone else is playing to hang on and finish where they're expected to finish. Huckabee's the one guy that can really upset the apple cart and show some real growth by doing better than expected in Iowa."
Over the years, the state has played a key role in the presidential selection process, culling large fields of candidates to just a handful of serious contenders. As Steve Grubbs, a veteran GOP strategist, put it, "Iowa doesn't decide who the nominee is going to be. It decides who it isn't going to be."
Voters here seem poised to play that role again in the Democratic race. Three candidates -- Sens. Hillary Rodham Clinton of New York and Barack Obama of Illinois and former Sen. John Edwards of North Carolina -- are essentially tied in a hard-fought contest that could dramatically boost or virtually end any one of their candidacies. The rest of the contenders are scrambling just to stay competitive.
On the Republican side, the import of Iowa's outcome is less certain. Three of the top candidates, Sen. John McCain of Arizona, former Sen. Fred Thompson of Tennessee and Giuliani are tacitly ceding first and second place as they focus more on New Hampshire and the states that follow. All of them are calculating that victory elsewhere will give them momentum heading into Feb. 5, when more than 20 states coast-to-coast will hold primaries or caucuses.
None, however, can afford a poor Iowa showing, and Giuliani in particular has been waging an aggressive direct-mail and radio advertising campaign in the state. "Our plan is to finish strongly," said Mike DuHaime, Giuliani's campaign manager, declining elaboration but insisting Iowa is not "make-or-break" for the ex-mayor the way it may be for other candidates.
Whatever happens Jan. 3, Iowa has already gone a long way toward shaping the Republican nominating fight, one of the most fluid and unpredictable in years. For months, Romney has been regarded as a top-tier candidate, despite his middling numbers in national polls, thanks to his place atop voter surveys in Iowa and New Hampshire. Now, Huckabee is enjoying the same benefit.
He has begun drawing extensive national media coverage and won the endorsement this week of a key Florida lawmaker, state Senate Majority Leader Daniel Webster. Also, for the first time, at Wednesday night's debate Huckabee was the subject of pointed and persistent criticism from his rivals, a fact he noted with delight.
"It's like my old pastor used to tell me," he joked. "When they're kicking you in the rear, it's just proving you're still out front."
But the two-hour session may have been just a taste of things to come. Economic conservatives have long denounced Huckabee's record on taxes in Arkansas, which Thompson touched upon in a candidate video broadcast during the debate. Huckabee also faced criticism from Romney for supporting in-state tuition for the children of illegal immigrants. No one touched on ethical issues that surround Huckabee's years as governor, but those are likely to draw more serious examination in the weeks ahead.
"A large part of his appeal is personality," said Gross, Romney's Iowa campaign chairman. "Can he sustain a serious vetting?"
That is a question few have bothered asking for most of the year, as Huckabee languished far back in the polls. His good fortune is that the race starts in Iowa, where voters still put a premium on a candidate's ability to impress in small settings, which is about the only way Huckabee could get his message across. Poor fundraising left him no choice but to campaign the old-fashioned way -- town-by-town, person-to-person -- and that has clearly paid off.
"He's got an enormous amount of political talent," said Q. Whitfield Ayres, a Republican pollster who has worked extensively in the South. "Iowa is the poster place for retail politics, and that has played to his strength: his in-person appeal."
Huckabee has also benefited greatly from the withdrawal of Sen. Sam Brownback of Kansas, a favorite of Christian conservatives, who shared Huckabee's opposition to abortion and same-sex marriage.
The former governor, who began televising ads just last week, addresses his Christian faith in his latest spot. He implicitly swipes at Romney and Giuliani, who have taken more conservative positions as they run for president.
"Faith doesn't just influence me; it really defines me," Huckabee said. "I don't have to wake up every day wondering, 'What do I need to believe?' "
Polling in Iowa is notoriously difficult, given the unusual nature of its caucuses, which require participants to show up at a designated time and place and invest several hours to cast a vote. Plenty of candidates have enjoyed bursts of momentum, then fallen back, leading some to predict more surprises before the year ends.
"None of us have ever experienced a Jan. 3 caucus," said Bob Haus, a 20-year veteran of Iowa politics who is managing Thompson's state campaign. "Let alone a race this volatile, which will probably be decided over the holidays.
"If any Republican operative tells you the game plan by which this will be determined, they don't know what they're talking about."