Romney, who had 10 hours earlier taken Huntsman to task for pushing Obama's policies in China, shot back that the Republican nominee should not be one that called Obama a "remarkable leader," as Huntsman did in a note to the president right before he resigned as Utah's governor.
"I think we serve our country first by standing for people who believe in conservative principles and doing everything in our power to promote an agenda that does not include President Obama's agenda," Romney said.
Huntsman, in one of his most aggressive responses in a debate, didn't skip a beat when host David Gregory threw the time back to him.
"This nation is divided, David, because of attitudes like that," Huntsman said. "The American people are tired of the partisan division. They have had enough."
Huntsman also earned the ire of Rep. Ron Paul's campaign, which blasted out in triplicate sometimes emails pointing out that the former Utah governor had backed a regional carbon market proposal and supported the Wall Street bailout and the Democrats' economic stimulus package.
After the debate, Paul's son, Sen. Rand Paul of Kentucky, continued the assault on Huntsman, but said he doesn't see much of a threat from the candidate.
"I'm not sure he really has a constituency," the senator said. "I don't think he's going to do very well."
Romney's campaign said the continued attacks by Huntsman against the front-runner spawned the verbal clash on stage and senior adviser Eric Fehrnstrom doubled down on the criticism, arguing that Huntsman is not a military general but someone who accepted a political appointment.
"Over the last two years Jon Huntsman has been working to implement the Obama agenda," Fehrnstrom said. "Mitt Romney has been working to oppose it. ... It's fine if Jon Huntsman wants to serve in the administration of Barack Obama, but we don't think that's the right experience for the Republican nominee who needs to go up against him in 2012."
Huntsman campaign manager Matt David countered that Romney struck a chord with the former Utah governor when he raised his service as ambassador and he felt a response was needed.
"It was a moment for him where he showed the people the biggest difference between Mitt Romney and Gov. Huntsman: when it comes to service he's going to put country ahead of politics," David said. "If Mitt Romney is arguing that what [Huntsman] should have been doing is raising money for politicians, I think the voters of New Hampshire are going to reward Gov. Huntsman for putting his country first."
The debate was the final chance for candidates to contrast themselves against their opponents before Tuesday's primary.
Romney continues to hold a strong lead in the state, according to the latest survey, though a tracking poll from Suffolk University/7News showed Huntsman slowly climbing to third place behind Romney and Paul.