DURHAM, N.H. - Republican presidential contenders voiced support last night for the Iraq war, while antiwar candidate Ron Paul warned that they risked dragging the party down to defeat in 2008.

"Even if we lose elections, we should not lose our honor," said former Arkansas Gov. Mike Huckabee, "and that is more important to the Republican Party."

Huckabee was in the majority and Paul the minority on the University of New Hampshire debate stage when it came to the war, which has emerged as the dominant issue of the presidential race.

The issue flared near the end of a 90-minute encounter in which all eight men on stage welcomed the absent Fred Thompson to the race with barbed humor and pointed advice.

"This is a nomination you have to earn," said former New York Mayor Rudy Giuliani. "Nobody's going to give it to you. Nobody's going to grant it to you."

Thompson, the former Tennessee senator and a veteran actor, told Jay Leno in a taped appearance last night on NBC's Tonight Show: "I'm running for president of the United States."

The debate among the GOP candidates unfolded several days before Gen. David Petraeus is due to deliver an assessment of President Bush's decision earlier this year to commit 30,000 more combat troops to Iraq, to give that nation's government time to develop.

Arizona Sen. John McCain, former Massachusetts Gov. Mitt Romney and Giuliani were among those who stressed their support for the war, at times even competing to show their commitment.

"The surge is apparently working," said Romney, referring to the increase in troops.

That brought an instant rebuke from McCain, who said: "The surge is working, sir; no, not 'apparently.' It's working."

The debate touched on familiar issues, and each of the men on stage looked for moments to appeal to their target constituents.

Huckabee, eager to win the support of social conservatives, said he supported a "human life amendment" to outlaw abortion. By contrast, Giuliani supports abortion rights and Romney favors letting states decide whether to permit or ban them.

Kansas Sen. Sam Brownback and California Rep. Duncan Hunter called for the resignation of Sen. Larry Craig (R., Idaho), who pleaded guilty to disorderly conduct in an airport men's room in an undercover police sting.

"It's important that the party stand for family values," Brownback said.

Brownback drew boos when he called for passage of a constitutional amendment to ban same-sex marriage. "I understand there is a divided audience," he said.

Giuliani responded to questions about his personal life by saying he is human and faces problems not uncommon to many Americans.

"I am not running as a perfect candidate for president of the United States," he said. "I'm running as a human being who has been very successful as a leader."