Lee0126bTAMPA, Fla.—During the 19th debate of this Republican presidential cycle, and the last one before next Tuesday’s crucial Florida primary, Mitt Romney flashed an aggressive side in an effort to separate himself from Newt Gingrich.

The clash between the two frontrunners began with the opening topic Thursday night in Jacksonville when Gingrich claimed that Romney was the most anti-immigrant of the four candidates.

“That’s simply inexcusable,” Romney scolded. “I’m not anti-immigrant. My father was born in Mexico … don’t use a term like that.”

Romney didn’t stop there. He called the charge “repulsive” and said Gingrich should apologize for his “over-the-top rhetoric” and “highly charged epithets.” The debate crowd responded by giving Romney one of the loudest cheers he has received in any debate so far.

Romney and Gingrich also fought over Fannie Mae and Freddie Mac.

Like he has done all week here in Florida, Romney attacked Gingrich for his $1.6 million contract as a Freddie Mac consultant.

“Speaker Gingrich was hired by Freddie Mac to promote them, to influence other people throughout Washington,” Romney said. “We should have had a whistle-blower and not a horn-tooter.”

Gingrich countered by stating that Romney owns shares of Fannie Mae and Freddie Mac. Gingrich wondered aloud “how much money [Romney has] made off of how many households that have been foreclosed.”

Romney said his investments are in a blind trust. But he also had another response ready: “Have you checked your own investments?” Romney asked Gingrich. “You also have investments in mutual funds that also invest in Fannie Mae and Freddie Mac.”

The audience again applauded for Romney.

Romney also got in a sharp jab after Gingrich made a plea that private enterprise should compete to build a moon colony. Romney said if an executive came to him with that idea, “I’d say you’re fired.”

Meanwhile, Rick Santorum, running a distant third in Florida polls, managed to have a strong night by appearing to be above the initial bickering, asking, “Can we set aside that Newt was a member of Congress … and that Mitt Romney is a wealthy guy?” He earned his own cheers by suggesting that they “leave that alone and focus on the issues.”

But later, Santorum did not hold back when it came to criticizing both Gingrich and Romney for once supporting types of health insurance mandates: “This is the top-down model that both of these gentlemen say they’re now against but they’ve been for.” … MORE >>

Read Edward Lee Pitts complete Web Extra report.