JACKSONVILLE, Fla. — Newt Gingrich cast Mitt Romney as the most anti-immigrant candidate of the four contenders for the Republican presidential nomination in campaign debate Thursday night in Hispanic-heavy Florida. "That's simply inexcusable," the former Massachusetts governor shot back, heatedly denying the accusation.
Romney quickly added that Gingrich's campaign had stopped running a radio ad that made the "anti-immigrant charge" after Florida Sen. Marco Rubio called on him to do so. Romney said to Gingrich concerning the ad, "I think you should apologize for it."
The exchange came near the beginning of the second debate in four days in advance of next Tuesday's Florida primary. Opinion polls make the race a close one, with two other contenders, former Sen. Rick Santorum of Pennsylvania and Texas Rep. Ron Paul, trailing far behind.
But Santorum drew applause from the audience when he called on the two front-runners to stop attacking one another and "focus on the issues."
"Can we set aside that Newt was a member of Congress ... and that Mitt Romney is a wealthy guy?" he said in a tone of exasperation.
That seemed unlikely, given the stakes in the primary now five days distant.
Gingrich picked up on the theme quickly, calling on moderator Wolf Blitzer of CNN to let the four candidates discuss the issues.
The audience booed, as if in agreement with Gingrich, but Romney jumped in, saying, "Wouldn't it be nice if people didn't make accusations somewhere else that they weren't willing to defend here."
Moments earlier, Romney and Gingrich had exchanged jabs over investments in Fannie Mae and Freddie Mac, two mortgage giants that played a role in the national foreclosure crisis that has hit Florida particularly hard.
Gingrich said Romney was making money from investments in funds that were "foreclosing on Floridians."
Romney quickly noted that Gingrich, too, was invested in mutual funds with Fannie Mae and Freddie Mac. He then added that the former House speaker "was a spokesman" for the two. That was a reference to a contract that one of Gingrich's businesses had for consulting services. The firm was paid $300,000 in 2006.
There were some moments of levity, including when Paul, 76, was asked whether he would be willing to release his medical records.
He said he was, then challenged the other three men on the debate stage to a 25-mile bike race.
He got no takers.
Romney and Gingrich had clashed repeatedly in the first debate of the week, held Monday in Tampa.
Gingrich's unexpected victory in the South Carolina primary last weekend upended the race to pick a Republican opponent for Democratic President Barack Obama in the fall, and Romney can ill afford another setback.
In the days since his loss, he has tried to seize the initiative, playing the aggressor in the Tampa debate and assailing Gingrich in campaign speeches and a TV commercial.
An outside group formed to support Romney has spent more than his own campaign's millions on ads, some of them designed to stop Gingrich's campaign momentum before it is too late to deny him the nomination.
Gingrich's performance in a pair of South Carolina debates are generally believed to have helped him to his victory there, and Romney's aides have expressed concern that the debate audience might benefit the former House speaker.
The issue was clearly on Romney's mind as he campaigned at a factory several hours before the debate began.
"There may be some give and take. That's always entertaining," he said. "If you all could get in there we'd love to see you all there cheering."
A voice from the audience responded that there were no more tickets, and Romney replied: 'No tickets? Just storm in."
Gingrich seemed far less confident as he campaigned his way into the debate.
He unleashed an attack reminiscent of his rhetoric a month ago when he was being outspent heavily on television and falling sharply in the polls just before the Iowa caucuses.
He accused Romney and Restore Our Future, the independent group, of dishonest ads, and said, "This is the desperate last stand of the old order. This is the kind of gall they have, to think we're so stupid and we're so timid."
He later told reporters he decided to sharpen his criticisms after Romney released his tax returns. "Here's a guy who owns Freddie Mac and Fannie Mae stock," Gingrich said. "He owns a Goldman Sachs subsidiary, which is foreclosing on Floridians. And on that front he decides to lie about my career? There's something about the hypocrisy that should make every American angry."
Romney released his income tax returns for 2010 and an estimate for 2011 after declining to do so in South Carolina.
Gingrich, also under pressure, disclosed the consulting contract one of his firms had with Freddie Mac, the government-backed mortgage giant that played a role in the foreclosure crisis that hit Florida especially hard. It showed payments of $300,000 in 2006 for unspecified consulting services.
Romney has pummeled Gingrich in the days since, calling him an influence peddler and a lobbyist who was taking money from the very organization that was harming Floridians.
Associated Press writers Brian Bakst and Kasie Hunt contributed to this story.