CONCORD, N.H. — As they come off bitter battles with Mitt Romney here and in Iowa, Senator McCain and Michael Huckabee expect a more civil race in South Carolina, where the campaign could come down to a largely two-man race between the maverick Arizona senator and the affable former Arkansas governor.

Both men campaigned confidently yesterday heading into today’s vote in New Hampshire, where Mr. McCain leads Mr. Romney and Mr. Huckabee appears comfortable with a likely third-place finish.

If today’s ballots match the latest polls, Messrs. McCain and Huckabee will head to South Carolina as front-runners, setting up a match-up between candidates who have rarely butted heads on the campaign trail to date.

Focusing almost exclusively on New Hampshire in recent months, Mr. McCain has seen little reason to go after Mr. Huckabee, whose victory in Iowa last week weakened his top rival, Mr. Romney. Similarly, Mr. Huckabee has not only avoided conflict with Mr. McCain, he has gone out of his way to defend him; he has criticized Mr. Romney for his negative ads against a man in Mr. McCain that he calls “a hero,” and at a GOP forum Sunday night on Fox News, he vouched for Mr. McCain after a question about his advanced age (he is 71), saying he met the senator’s mother, who remains active at age 95.

Mr. Huckabee said yesterday that he expected little to change if the two become more direct competitors in South Carolina. “It will be a civil race,” he told The New York Sun as he greeted voters at the Barley Grill. “And the good thing is we’ll have good mutual respect for each other. It will be clean and fair.”

Mr. Huckabee did not explicitly reference Mr. Romney in his comments, but he has accused the former Massachusetts governor of running a “dishonest” campaign. Advisers to the candidates in South Carolina each cited different bases of support. For Mr. Huckabee, it is the evangelicals and social conservatives who turned out in droves for him in Iowa, but who are less dominant in New Hampshire. For Mr. McCain, a Vietnam veteran who was held as a prisoner of war, it is the state’s large population of military families.

“No one is questioning John McCain’s credibility as far as that goes. They would be a fool to do so,” the chairman of Mr. Huckabee’s campaign in South Carolina, Michael Campbell, said yesterday in a telephone interview. He said Mr. Huckabee, who did not serve in the military, would try to appeal to that constituency by touting his proposal for a “Veterans Bill of Rights.”

Mr. Huckabee has opened up a comfortable lead in South Carolina, with polls showing him ahead of Messrs. Romney and McCain by at least seven points, although Mr. McCain would expect a bounce if he wins New Hampshire today. Mr. Campbell also cited the fact that Mr. McCain was forced to cut much of staff in the state last summer when his campaign nearly collapsed due to a cash shortfall. “Senator McCain is certainly going to have a lot of making up to do in South Carolina,” said Mr. Campbell, who ran unsuccessfully for lieutenant governor in 2006.

Mr. Huckabee, however, had just four paid staffers of his own in the state until this week, when the campaign sent more than a dozen in from Iowa, Mr. Campbell said. The head of Mr. McCain’s South Carolina campaign, state attorney general Henry McMaster, dismissed the suggestion that his organization was weakened, saying he retained chairmen in every county and more than 1,000 volunteers across the state. Aside from the departure of paid staff, he said, little had changed. “Everyone’s still in place and supportive,” Mr. McMaster said in a phone interview.

He said he expects Mr. Huckabee to run a more respectful race, calling him a nice man. Mr. McCain’s hopes for the GOP nomination in 2000 evaporated in South Carolina after a nasty race with then-Governor Bush, in which Mr. McCain was the victim of a whisper campaign that suggested — falsely — that he had a child out of wedlock. “I don’t think there’s any lingering damage to him,” Mr. McMaster said.

The South Carolina primary will be held on January 19, four days after Republicans vote in Michigan, where Mr. McCain may have a rematch with Mr. Romney.

He is planning to head directly to Michigan tomorrow morning, but he will spend only a few hours there before heading to South Carolina.

Mr. Huckabee is expected to pay much more attention to the election in South Carolina, with an eye on the Florida primary on January 29. With a deep reserve of cash, Mr. Romney could also remain a threat even if he loses New Hampshire, and Fred Thompson has said he will make a big push there in an effort to salvage his campaign.

For one more day, however, the focus remains on the Granite State.

Mr. McCain stumped across six cities yesterday, delivering an abbreviated, 10-minute version of a stump speech he has given countless times. Taking advantage of mild temperatures in the 40s, he held outdoor rallies in Concord and Manchester, drawing several hundred people to each.

Mr. Huckabee dispensed with his speech altogether while stopping at two Concord eateries, content to simply greet supporters and, at the Barley Grill restaurant, sample a “Huckaburger” created in his honor. Owner Brian Shea said he designed the burger with Mr. Huckabee’s health in mind — the hefty former governor famously lost more than 100 pounds on a diet — using leaner bison meat and adding spinach. And unsurprisingly, Mr. Huckabee gave the “Huckaburger” an enthusiastic thumbs-up.

Asked if it was better than burgers in his native Arkansas, he paused and said: “There’s a primary here tomorrow. It’s the best burger I’ve ever had in my life.”