DORAL, Fla. — Newt Gingrich and Mitt Romney urged conservatives to back off aggressive anti-immigration policies as the Republican presidential candidates vied for Hispanic votes Friday, a day marked by heightened tensions entering the final weekend before Florida's primary.

"I'm very concerned about those who are already here illegally and how we deal with those 11 million or so," Romney said. "My heart goes out to that group of people. ... We're not going to go around and round people up in buses and ship them home."

The compassionate approach, like Gingrich's calls for politically practical reform, was aimed at improving the Republican Party's tarnished reputation among Hispanics. Both men delivered speeches Friday to the same group of Hispanic leaders gathered in Miami but avoided — at least briefly — criticizing each other in what now looks like a two-man race for the nomination.

Any calls for temperance on immigration didn't apply to personal attacks elsewhere.

The former House speaker released a new television ad in Florida using former Arkansas Gov. Mike Huckabee to question Romney's integrity. "If a man's dishonest to get a job, he'll be dishonest on the job," Huckabee says in the ad.

However, Huckabee said he didn't approve of his appearance in the ad and had been quoted out of context. Reiterating his stand against making a primary endorsement, he wrote on his PAC website: "My hope is to defeat Barack Obama and win majorities in both the House and Senate, not to attack any of the presidential candidates who might be our nominee."

Romney flashed a newfound confidence as he campaigned the day after delivering a strong debate performance. "I've had the fun of two debates where I had to stand up and battle, and battling was fun and battling was won," he told cheering supporters gathered at Cape Canaveral.

He later likened Gingrich's complaints to "Goldilocks," the fairy tale character who complained of the temperature of her porridge.

Tensions boiled over between the Gingrich and Romney representatives at a stop in Delray Beach. Gingrich spokesman R.C. Hammond confronted Utah Rep. Jason Chaffetz, who is among several high-profile Romney surrogates tailing the former House speaker.

Surrounded by reporters and cameras, Hammond goaded Chaffetz for employing a tactic that even 2008 presidential nominee John McCain has called into question. McCain is a Romney backer who on Friday said he would discourage that type of infiltration.

"What you're saying is you're disregarding the advice of one your top endorsers?" Hammond asked Chaffetz.

"Speaker Gingrich has routinely said he would follow the president from place to place. We think it's a good idea," Chaffetz responded, referring to Gingrich's threat, if he wins the GOP nomination, to follow President Barack Obama from city to city to get the last word.

The outburst overshadowed a detailed discussion about immigration, in which the rivals called for democracy in Cuba and across Latin America, touching a theme that caused clashes between the GOP front-runners at Thursday night's debate in Jacksonville.

Immigration is a flashpoint issue in Florida for the GOP candidates, who are trying to strike a balance between sounding compassionate toward immigrants and firm about stemming the tide of illegal workers. The state has roughly 1.5 million Hispanic voters.

Gingrich pushed for a measured approach to revising the nation's immigration laws, "because any bill you write that is comprehensive has too many enemies." The former House speaker says he wants stricter border control, faster deportation proceedings and a guest-worker program for certain immigrants.

If elected, Gingrich said he would bring to bear "the moral force of an American president who is serious about intending to free the people of Cuba and willingness to intimidate those who are the oppressors and say to them, 'You will be held accountable.'"

Romney said the United States needs to work harder to promote democracy across Latin America and elsewhere. He compared it to selling soda: "We convince people around the world to buy a brown, caramel-colored water called Coca-Cola and to pay like a half day's wage for it. And they'll buy it. It's unbelievable. We're able to convince people of things that sometimes you scratch your head. ... And yet democracy, we don't sell that so well."

Military dictatorships allied with the United States ruled much of South America in the 1970s, but most nations returned to democracy in the 1980s.

Romney also pledged to appoint a Latin American envoy and to create a task force to focus on drug trafficking and other issues.

Hours after the speech, Romney also won the coveted endorsement of Puerto Rico Gov. Luis Fortuno, who joined Romney at an Orlando campaign stop late in the day. Romney and Gingrich said earlier that Puerto Rico should be granted statehood if local voters approve a looming referendum.

Opinion polls show a close race, with a slight advantage for Romney. Two other contenders, former Sen. Rick Santorum of Pennsylvania and Rep. Ron Paul of Texas, were far behind.

Paul has already made clear his intention to skip Florida in favor of smaller states that cost less to campaign in. On Friday, he began a two-day visit to snowy Maine.

Santorum, who had been campaigning aggressively here, conceded that he's better off at home, sitting at his kitchen table Saturday doing his taxes instead of campaigning in a state where he can't keep up with the GOP front-runners.

Outside advisers were urging him to pack up completely and not spend another minute in Florida, where he is cruising toward a third straight loss.