Kevin Madden, Romney's national press secretary, said he thought McCain "fell flat in whatever point he was trying to make."

As for the overall effect of the negative, personal tone that McCain and Mike Huckabee took, Madden said that will be for voters to decide.

Huckabee, riding momentum from his strong first-place finish in Thursday's Iowa caucus, took a stab at Romney early in the debate during a segment on foreign policy.

Romney told Huckabee he should try to characterize his position on the troop surge a certain way, to which Huckabee shot back "which one?"

"You know, we're wise to talk about policies and not to make personal attacks," Romney said.

Madden said Romney "kept his tone and tenor about the issues" and does not have to get down to things personally. He said the fact Romney seemed to be the overall target proves he is still on top in New Hampshire.

"If they are not attacking you, that means they are not worried about you," Madden said.

Obama, who won the kickoff Iowa caucus on Thursday, was in the spotlight often during the debate among the Democrats, and his remaining rivals — Clinton, former Sen. John Edwards and New Mexico Gov. Bill Richardson — can ill afford for him to gain a victory in New Hampshire's primary as well.

"You said you would vote against the Patriot Act. You came to Senate, you voted for it. You said you would vote against the Iraq war; you came to the Senate and voted for" funding, Clinton said of Obama. "I think we should get into examining everybody's record," she said.

Obama's candidacy has soared on his pledge to bring change to Washington, and Clinton sought to blunt his advantage while sticking to her own campaign-long theme. "I have 35 years of experience making change," she said.

Edwards, second-place finisher in Iowa, worked throughout the debate to align himself with Obama as an advocate for change in Washington and described Clinton as a defender of the status quo. "Every time he speaks out for change, every time I fight for change, the forces of status quo are going to attack," Edwards said.

"I didn't hear these kind of attacks from Sen. Clinton when she was ahead," he said. "Now that she's not, we hear them."

There were a few moments of humor.

"I've been in hostage negotiations that are a lot more civil than this," Richardson, a one-time diplomat, said at one point.

Asked what she could say to voters who don't find her likable enough, and seem to like Obama more, Clinton drew laughter. "Well, that hurts my feelings. ... But I'll try to go on."

She said she agreed that Obama was likable, then added, "I don't think I'm that bad."

That drew a wry response from Obama, who said, "You're likable enough, Hillary."