Aides say Romney's attacks are partially a response to increasingly angry rhetoric from Gingrich, who on Sunday called the former Massachusetts governor "somebody who is a pro-abortion, pro-gun-control, pro-tax-increase liberal." Gingrich also accused Romney of lying. "I don't know how you debate a person with civility if they're prepared to say things that are just plain factually false," Gingrich said.
Romney's campaign responded immediately Sunday, starting with the candidate and continuing with statements from top surrogates who cast Gingrich's assault as an unfair attack on Romney's character.
"Mitt Romney is man of impeccable character," said New Jersey Gov. Chris Christie. "It offends me that Newt Gingrich would attack the character of Mitt Romney."
Former Minnesota Gov. Tim Pawlenty called the attacks "over the line."
In what has become a wildly unpredictable race, the momentum has swung back to Romney, who was staggered by Gingrich's victory in South Carolina on Jan. 21. Romney has begun advertising in Nevada ahead of caucuses there next Saturday, illustrating the challenge ahead for Gingrich.
An NBC News/Marist poll published Sunday showed Romney with support from 42 percent of likely Florida primary voters, compared with 27 percent for Gingrich.
Santorum, trailing in Florida by a wide margin, skipped campaigning to be with his 3-year-old daughter, Bella, who was hospitalized. He planned a pair of campaign appearances in Missouri on Monday.
Texas Rep. Ron Paul, who has invested little in Florida, also looked to Nevada. The libertarian-leaning Paul is focusing more on gathering delegates in caucus states, where it's less expensive to campaign. But securing the nomination only through caucus states is a hard task.
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