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No more Mr. Nice Newt?

Newt Gingrich, after being walloped by negative ads in Iowa and finishing fourth, is planning a far more aggressive strategy to "contrast" himself against Mitt Romney in the run-up to the South Carolina primary.

Voters will get a glimpse of Gingrich's post-Iowa tone during back-to-back debates in New Hampshire ahead of that state's primary on Tuesday. The former House speaker told Fox News on Saturday that he won't be "mean-spirited" but will talk about the differences between himself and the former Massachusetts governor.

While Gingrich is vowing to shun the kind of "negative" ads he claims were responsible for bringing him down in Iowa, his campaign and his campaign's supporters are certainly dialing up the heat on Romney.

For starters, Gingrich has started to talk about Romney's record on abortion.

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"I am genuinely right-to-life -- Romneycare includes tax-paid abortions," Gingrich said Saturday. His campaign is planning to air an ad "soon" on the abortion issue.

While Gingrich claims Romney's abortion record is sullied by his state's health care overhaul -- or "Romneycare" -- the candidate has said the state faced a court order to cover abortions, and it's misleading to suggest he ever pushed taxpayer funding for abortions. Romney's campaign also released a letter from several conservative leaders Saturday praising his record on abortion and marriage.

But Gingrich has repeated the abortion charge on a new web site his campaign rolled out called NotRomney.org. The site includes a flier that states "Mitt Romney has a record of supporting taxpayer funded abortions."

It also accuses Romney of backing "higher taxes" and nominating "liberal, activist judges," while arguing that he "is not electable."

The tough approach comes as new polls show Romney gaining steam out of the Iowa caucuses, which he narrowly won.

Most polls show him retaining a double-digit lead in New Hampshire, while regaining the lead nationally and in South Carolina. New Hampshire has, according to many analysts, become a battle for second place -- among Gingrich, Ron Paul, Jon Huntsman and Rick Santorum, who has surged out of the Iowa contest after finishing just a few votes behind Romney.

Romney and his supporters are looking for a shut-out victory in New Hampshire.

"We don't just need a win in New Hampshire. We need a landslide in New Hampshire," South Carolina Gov. Nikki Haley, campaigning with Romney on Saturday, told supporters.

Romney's opponents are trying to hold down his margin.

While Gingrich complained during the Iowa contest about the massive amounts of money being spent by a pro-Romney PAC, a PAC supporting the former speaker recently obtained a scathing 30-minute video about Romney's time at Bain Capital.

Clips of the video portray Romney as a wealthy businessman who used the firm as a vehicle to "reap massive rewards for himself and his investors" at the expense of others.

Asked about the film, Gingrich said "I've not looked at it." He added, "If it's accurate, then it's accurate."

Romney's campaign, in a statement Saturday, said "it is sad when any American loses their job," but criticized Gingrich's supporters for pushing the film.

"It's puzzling to see Speaker Gingrich and his supporters continue their attacks on free enterprise," spokeswoman Andrea Saul said. "This is the type of criticism we've come to expect from President Obama and his left-wing allies at Moveon.org. Unlike President Obama and Speaker Gingrich, Mitt Romney spent his career in business and knows what it will take to turn around our nation's bad economy."

The sparring between Romney and Gingrich appears to have left Santorum to play a more positive role in the race. He said Saturday in New Hampshire that he's "not going to be critical" of Romney's tenure at Bain.

"Did some of his companies fail? Yes. I guarantee you, he didn't invest in those companies so they would fail," Santorum said. "I'm sure he wanted to invest in those companies so he could make money, not lose."

He argued that Washington does not need a "manager" like Romney and other candidates, but claimed all he was doing at Bain was "capitalism."

Continuing his Iowa strategy, Santorum is plugging away in New Hampshire with a host of local meet-and-greets with primary voters.

On Saturday, Santorum stood on a picnic table in Amherst, N.H., to address a crowd of about 300 people.

"Make sure your vote Tuesday is in line with how you live here in New Hampshire," he told them.

Santorum and other candidates will have a chance at the upcoming debates to arrest Romney's rise in the polls. They gather at Saint Anselm College Saturday night for the first debate, followed by another Sunday morning.

Paul is running in second position in New Hampshire in most recent polls, with Gingrich, Santorum and Huntsman competing to overtake him.

Huntsman has staked his campaign on New Hampshire, after having ignored Iowa. Meanwhile, Texas Gov. Rick Perry, after finishing fifth in Iowa, is polling at 1 percent in New Hampshire.