An accelerated primary calendar gives Mike Huckabee little time to savor his Iowa win and Mitt Romney a fleeting chance to stage a comeback in New Hampshire, all while John McCain angles to seize the conversation with a reprise of his 2000 primary victory.
The pivotal moment in the five-day mini-campaign could come Saturday, when the GOP presidential field convenes in Manchester for their only debate between Thursday's caucuses and next Tuesday's primary.
For Huckabee, the challenge is to capitalize on his upset win in Iowa, where overwhelming support from evangelicals cemented a victory that had been projected in polls during the past month.
It's a different story in secular New Hampshire, where he pulled only 10 percent of the vote in a recent survey.
"We're going to convert a lot more people in New Hampshire in the next five days," he joked to reporters on his plane from Iowa to New Hampshire.
Turning serious, he added: "If you look at the numbers, there are a lot of people who were out there voting for us. And it doesn't explain numbers in Delaware, Michigan, places like that."
Huckabee also has to overcome questions from the party establishment, which doesn't trust the former Arkansas governor on
immigration and taxes and thinks he sounds too liberal on health care, welfare and poverty programs.
For Romney, who surrendered a double-digit lead in Iowa and has seen his front-runner's stature similarly challenged by McCain in New Hampshire, the former Massachusetts governor must fight off the prospect of a loss in his own backyard.
The one-two punch he hoped for in Iowa and New Hampshire has been replaced by the need to land a desperate haymaker on either Huckabee or McCain - or both.
"I let one guy slip by me, hats off to him, he did a nice job. We're not going to let that happen here in New Hampshire - anywhere else," Romney told local supporters who greeted him in Portsmouth as his plane returned from the Midwest.
McCain, meanwhile, must hope that he can again attract the support of New Hampshire independents, who comprise the largest voting bloc in the state, now that Barack Obama has diminished some of the intrigue in the Democratic race with a sound thumping of Hillary Rodham Clinton in Iowa.
McCain did so in 2000, when the Arizona senator's maverick nature attracted independent voters, who propelled him to an 18-point victory over then-Texas Gov. George W. Bush.
Rudy Giuliani, once the national front-runner, is also competing in the Granite State, but he was a non-factor in Iowa and finished sixth.
The former New York mayor is pinning his hopes on victories in big-ticket states like New York and California that vote later in the process.
Former Tennessee Sen. Fred Thompson finished Iowa tied for third with McCain, who largely skipped the caucus campaign, while Texas
Rep. Ron Paul finished fifth but vowed to remain in the race.
"Huckabee starts with a smaller base than he did in Iowa," Dean Lacy, a government professor at Dartmouth College, said, noting entrance polls that showed Huckabee outpacing Romney among Iowa evangelicals and lower-income voters.
"Romney obviously has to win," Lacy added. "The problem for him is that there is no state other than South Carolina where he can beat expectations. He's expected to win in New Hampshire because it borders his home state, and he can't beat expectations in Michigan, because it's his family's home state. It sets up for John McCain to win in New Hampshire."
In a poll conducted for The Associated Press of voters entering Iowa's caucuses, Huckabee voters indicated values outranked electability in importance.
Six in 10 of his backers said the most important quality in picking a candidate was someone who shared their values, while a third of his supporters said he says what he believes.
Fewer than one in 20 said they thought he had the best chance of winning in November.
Meanwhile, faith was a determining factor for many Republican caucus participants.
A significant chunk of Huckabee supporters - eight in 10 - said they are born again or evangelical Christians, compared to less than half of Romney's backers.
Huckabee is a former Southern Baptist minister who openly appealed to evangelicals, while Romney is trying to become the first Mormon elected president.
Some evangelicals openly call his Church of Jesus Christ of Latter-day Saints a cult.
Nearly two-thirds of Huckabee voters also said it was very important that their candidate share their religious beliefs, compared to about one in five of Romney's.
Huckabee will enjoy little of that advantage in Yankee New Hampshire, where Romney is widely admired for his leadership of neighboring Massachusetts, perhaps the bluest Democratic state in the nation.
At the same time, Romney has to fend off McCain, who has bought himself some time in the nomination fight by declaring his campaign really begins in New Hampshire.
Romney urged everyone to step back and take a broader look as they fine-tune the picture Iowans began to bring into focus on Thursday.
"Washington is broken and we're going to change that, and Iowa said that tonight," the one-time venture capitalist told a crowd in West Des Moines, Iowa. "We need new faces in Washington, and I intend to be one of them."