MYRTLE BEACH, S.C. — In their last debate before the nation's first Southern primary, the Republican presidential candidates made contrasting appeals last night in a state packed with conservative GOP voters.

John McCain, seeking to maintain momentum from his New Hampshire win this week, pledged to "stop out-of-control spending" by the federal government. "I'm called the sheriff by my friends in the Senate who are the appropriators," he said.

Mike Huckabee, the Iowa caucus winner, said Republicans need to be just as interested in "single moms who are working two jobs and still just barely paying the rent as we are the people at the top of the economy."

Mitt Romney, who won the Wyoming caucuses, stressed his business background and said more tax cuts would help the nation head off a potential recession. "I know how to bring change and I will change Washington," he said.

Ron Paul, a Texas congressman, again criticized the Republican Party for too much spending, overextending the military and seeking to impose U.S. values on other nations. "We actually have lost our way," he said.

Fred Thompson and Rudy Giuliani, who are looking for their first victories in the nominating contests, also promoted tax cuts at the debate last night sponsored by Fox News Channel and the South Carolina Republican Party.

BUSH WON IN 2000

In the past, the South Carolina GOP primary has been something of a good-luck charm for the winner: Since 1980, each has gone on to claim the party's presidential nomination. George W. Bush won a crucial and bitterly fought primary in 2000 over McCain. The results in this primary, set for Jan. 19, could prove different. Hours before the debate, two new polls showed McCain leading Huckabee in South Carolina. Romney was in third.

Some of the debate's sharpest exchanges came between the two Southerners, Thompson and Huckabee.

Thompson, a former Tennessee senator, said the former Arkansas governor backs "liberal" spending and foreign policies. Huckabee responded in part by invoking an Air Force saying: "If you're not catching flak, you're not over the target. ... I must be over the target."

McCain, a former Navy pilot and Vietnam prisoner of war, reminded the audience of his support for the Iraq war. Thursday was the one-year anniversary of President Bush's announcement that he would temporarily boost U.S. troop levels in Iraq.

MCCAIN 'TRUTH SQUAD'

The Arizona senator said he took heat for backing the increase at the time, and "I'm the only one on this stage that did." That drew a rebuke from Giuliani, who said, "I supported the surge; I've supported it throughout." McCain replied that he "condemned" the previous Iraq plan "and called for the change in strategy. That's the difference."

McCain's campaign, seeking to avoid a repeat of 2000, has set up a "truth squad" to fight any allegations against him.

Eight years ago, negative campaigning included suggestions that McCain's adopted daughter from Bangladesh was illegitimate. This time, his campaign sent out mailers featuring a picture of his wife, Cindy, and the daughter, Bridget, whom the McCains adopted from Mother Teresa's orphanage.

Huckabee, a Baptist minister, is seeking support from the many religious conservatives in South Carolina, a strategy similar to one he used in Iowa.

James Guth, a political scientist at Furman University in Greenville, S.C., said conservative white Protestants make up 40 percent to 50 percent of the GOP electorate here. He said the bloc is comparable in size to the evangelical voters in Iowa, though the religious community here is more diverse politically. For example: Bob Jones III, chancellor of the fundamentalist university that bears his family's name, has endorsed Romney, who is Mormon.

Giuliani is concentrating on Florida, whose primary is Jan. 29.