MIAMI — Newt Gingrich slammed GOP presidential rival Mitt Romney for "carpet-bombing" his record ahead of Tuesday's presidential primary in Florida, trying to cut into the resurgent front-runner's lead in the final 48 hours before the vote.
On the defensive after barrage of attacks from Romney and a political committee that supports him, Gingrich said Romney had lied and the GOP establishment had allowed it.
"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 during appearances on Sunday talk shows. "I think the Republican establishment believes it's OK to say and do virtually anything to stop a genuine insurgency from winning because they are very afraid of losing control of the old order."
Despite Romney's effort to turn positive, the Florida contest has become decidedly bitter and personal. Romney and Gingrich have tangled over policy and character since Gingrich's stunning victory over the well-funded Romney in the South Carolina primary Jan. 21.
Showing no signs of letting up, Gingrich objected to a Romney campaign ad that includes a 1997 NBC News report on the House's decision to discipline the then-House speaker for ethics charges.
"It's only when he can mass money to focus on carpet-bombing with negative ads that he gains any traction at all," Gingrich said.
Gingrich acknowledged the possibility that he could lose in Florida and pledged to compete with Romney all the way to the party's national convention this summer.
An NBC/Marist poll showed Romney with support from 42 percent of likely Florida primary voters and Gingrich slipping to 27 percent.
While Romney had spent the past several days sharply attacking Gingrich, he pivoted over the weekend to refocus his criticism on President Barack Obama, calling the Democratic incumbent "detached from reality." The former Massachusetts governor criticized Obama's plan to cut the size of the military and said the administration had a weak foreign policy.
Gingrich's South Carolina momentum has largely evaporated amid the pounding he has sustained from Romney's campaign and the pro-Romney group called Restore Our Future. They have spent some $6.8 million in ads criticizing Gingrich in the Florida campaign's final week.
Gingrich planned to campaign Sunday in central Florida, while Romney scheduled rallies in the south. He was also looking ahead to the Nevada caucuses Feb. 4, airing ads in that state and citing the endorsement Sunday of the Las Vegas Review-Journal, Nevada's largest newspaper.
Gingrich collected the weekend endorsement of Herman Cain, a tea party favorite and former presidential hopeful whose White House effort foundered amid sexual harassment allegations.
Former Pennsylvania Sen. Rick Santorum, trailing in Florida by a wide margin, planned to remain in Pennsylvania where his 3-year-old daughter, Bella, was hospitalized, and resume campaigning as soon as possible, according to his campaign. She has a genetic condition caused by the presence of all or part of an extra 18th chromosome.
Texas Rep. Ron Paul has invested little in the Florida race and is looking ahead 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.
Gingrich appeared on "Fox News Sunday" and ABC's "This Week." Paul was on CNN's "State of the Union."
Associated Press writer Philip Elliott in Tampa contributed to this report.