Updated 9:05 PM ET
PORTSMOUTH, N.H. - As he sought to consolidate his strong support in New Hampshire before heading to Iowa, Mitt Romney opted on Tuesday for mockery over menace in criticizing Newt Gingrich, even as his GOP presidential rival denounced Romney's attack ads and record as Massachusetts' governor.
Appearing in Portsmouth, Romney noted a statement that Gingrich's campaign director compared the former House speaker's inability to qualify for the Virginia ballot as a setback comparable to Pearl Harbor from which they would recover.
In another appearance in Londonderry, Romney also took a subtle swipe at Gingrich for a 2008 speech in which he praised Romney's health care plan and the individual health insurance mandate at its heart. "I'm familiar with the fact that he supported individual mandates in the past and was supportive of generally of the plan in Massachusetts, and he's changed his view in the election year," Romney said.
Asked to respond to Romney's comments, Gingrich accused Romney of ducking a one-on-one debate, even though the two men have appeared together at all of the GOP debates.
"He's buying millions of dollars in attack ads . paid for by his millionaire friends," Gingrich said on CNN. "Now, I'd like to have him have the courage to be on the same stage and defend his ads and explain his record of raising taxes . and frankly, explain why he wasn't a job-creating governor."
Romney was more circumspect in criticizing Rep. Ron Paul, who has found himself immersed in considerable controversy over a series of newsletter writings. "I haven't seen the Ron Paul newsletters. From what I understand, he repudiated them and from what I understand, that was the right course for him to take."
In Londonderry, Romney also sought to project an aura of bipartisanship, seeking to appeal to independent-minded New Hampshire voters who want to see an end to Washington gridlock.
"I think there are Republicans and Democrats who will sit down, work together, and say we are going to put America on a sound financial footing ... I can tell you, I'm not going to spend my time bashing democrats and attacking them day in and day out, because that makes it impossible to sit down and work together," he said.
Romney picked up the endorsement of the conservative-leaning Boston Herald tabloid, which called him the "one candidate in the Republican field with the integrity, the experience, the organizational strength and the intelligence to beat Barack Obama."
Later Tuesday, appearing in Davenport, Iowa, at his kick-off event for the week leading up to the caucuses, Romney paid tribute to the Hawkeye State.
"Iowa was built by men and women who pursued their dreams," he told a standing-room crowd of several hundred people at the Blackhawk Hotel. "Pioneers came here for a better life. They tilled the land and planted crops. They took prairie and turned it into community. And those who followed them built great institutions of learning and industries as diverse as the nation. Iowa and America were built by free people and free enterprises pursuing happiness in their own ways." ?
Obama's team, meanwhile, continue to hammer Romney, with spokesman Ben LaBolt echoing Vice President Joe Biden's earlier criticism that Romney would usher in a return to what they consider failed GOP economic policies.
"While President Obama is fighting for an economy that rewards hard work and responsibility and provides every American with a fair shake, Mitt Romney believes in skewing the playing field toward those at the top while leaving Americans facing a challenge on their own," LaBolt said.
Naureen Khan contributed