JACKSONVILLE -- The populist faced off with the patrician.

Newt Gingrich was expected to take it to Mitt Romney on Thursday night, after savaging Romney’s ties to Goldman Sachs and his bank accounts in Switzerland and the Cayman Islands.

But Romney unexpectedly struck first when it came to one of the most treacherous of Florida political issues: immigration — and Gingrich’s claims in a Spanish-language radio ad that Romney was “anti-immigrant.”

“That’s simply inexcusable. That’s inexcusable,” Romney, said glaring at Gingrich. “And, actually, Senator Marco Rubio came to my defense and said that ad was inexcusable and inflammatory and inappropriate.”

Gingrich edited the ad after Rubio made those comments Wednesday to The Miami Herald. The following day, the morning of the debate, Rubio praised Gingrich.

But the damage was done.

Wild cheers greeted Romney’s salvo. A few days before, at Tampa’s Monday debate, the crowd was eerily quiet at the request of NBC television officials. The crowd was back Thursday. But now, the people in the hall were with Romney in Jacksonville, a stronghold for the Republican where the GOP establishment has rallied behind him.

On the campaign trail, though, away from the air-conditioned comfort of the University of North Florida’s debate hall, Gingrich had the crowds. Hundreds, perhaps thousands, showed up to hear the former House Speaker speak. Romney had smaller, more made-for-TV events.

Thursday night’s debate was supposed to be the debate that would prove critical in Tuesday’s Republican primary. Yet, there was no clear winner or loser, but Romney had the edge. Polls show the race is exceedingly close, but Romney might be surging amid a statewide ad blitz.

Yet the debate lived up to its nickname: The River City Rumble.

Ron Paul and Rick Santorum played the roles of foils, chiding the frontrunners for bickering and, at times, not answering questions.

This was also the debate where Florida took center stage. The problems in the nation’s largest swing state are the problems of the nation writ large: Unemployment, home foreclosures, immigration. Cuba, Israel policy and space travel got some airtime, too.

When Romney lit into him over immigration, Gingrich held firm. He smiled. He wanted to paint Romney as heartless, out of touch.

“You tell me what language you would use to describe somebody who thinks ... that deporting a grandmother or a grandfather from their family” is a good idea, Gingrich said.

Romney’s retort: “You know, our problem is not 11 million grandmothers.”

More cheers.

Then Romney stumbled.

CNN debate moderator Wolf Blitzer asked why Romney ran his own Spanish-language ad that accused Gingrich of calling Spanish “the language of the ghetto.”

“I haven’t seen the ad, so I’m sorry. I don’t get to see all the TV ads. Did he say that?” Romney asked. “I doubt that’s my ad, but we’ll take a look and find out. There are a bunch of ads out there that are being organized by other people.”

Oops.

It was an ad by Romney, who at a previous debate was able to cite specifics of other anti-Gingrich ads of a third-party group.

Later, when asked about how mortgages should be regulated, Romney eschewed offering specifics in favor of attacking Gingrich for working as a consultant to mortgage-giant Freddie Mac. Gingrich struck back, pointing out Romney has profited from investments in Freddie Mac and Fannie Mae.