At the GOP debate in Las Vegas, Perry took the issue of immigration – which has plagued his campaign recently, as rivals portrayed him as weak on the issue – and turned it against Romney.
"The idea that you stand here before us and talk about that you're strong on immigration, is on its face the height of hypocrisy," Perry said to Romney.
"You stood here in front of the American people and did not tell the truth that you had illegals working on your property,” Perry said. “The idea that you can sit here and talk about any of us having an immigration issue is beyond me.”
Romney, who had faced the issue – raised in a Boston Globe article years ago -- when he previously ran for president , said he fired the undocumented worker from doing his lawn as soon as he learned that he was in the country unlawfully.
Perry shot back that he continued to employ undocumented workers for a year after the first incident came to light. Romney, growing increasingly angry, said that he did not know the lawn care company had continued to use undocumented workers, in contrast, he said, to its promise to him that it would only have people legally eligible to work. Romney said that he stopped using the company after learning it continued to send undocumented immigrants to work on his lawn.
Romney fired back at Perry by saying that when he was governor of Massachusetts, he did not provide a magnet for undocumented immigrants, unlike Perry, he said.
He told Perry that he provided a magnet for undocumented immigrants to settle in Texas by supporting a law that allows people who are in the country unlawfully to attend public colleges at in-state tuition rates.
"You said I don't want to build a fence," Romney said. "You talk about magnets -- you put in place a magnet."
Perry has said that the in-state tuition law was right for Texas, but that he does not necessarily think that it should be a national law. In the past, he has said it would be wrong to punish the children of undocumented immigrants by making it difficult for them to pursue a higher education, and having them in classrooms would be preferable than having them in the streets.
But at the Nevada debate, he did not defend the in-state tuition law with sympathetic comments about the undocumented. Instead, he said he was indeed tough on immigration because he opposes any policy which would be a form of amnesty and supports building a “strategic fence,” not one along the entire U.S.-Mexican border because, he said, it would be too expensive and take too long to construct.
Minnesota Rep. Michele Bachmann said that she would build a double fence and, in a reference to Perry and in-state tuition, would not allow any breaks for the undocumented.
Bachmann also said she would deal with “anchor babies,” a controversial term used to refer to children born in the United States to undocumented immigrants. Bachmann suggested she would not allow automatic birthright citizenship.
She vowed, too, to make English the “official language” of the United States.
But the most problematic candidate as far as immigration, Bachmann said, was President Obama, whose “uncle and his aunt who have been allowed to stay in this country despite the fact that they’re illegal.”
Former Godfather’s Pizza CEO Herman Cain said he favored a comprehensive border protection plan, including troops.
He did not directly answer the moderator’s question about electrifying the border, a concept he pushed recently, eliciting controversy.
At a Tea Party-sponsored rally in Tennessee, Cain proposed building an electric border fence that could kill people trying to cross it. At the rally he also said he would consider using military troops “with real guns and real bullets” to stop unlawful border-crossers.
At the debate, held at the Venetian Resort Hotel Casino in Las Vegas, a man in the audience told the candidates that most Latinos were not undocumented immigrants, and what message did they have for the roughly 50 million Latinos in the nation.
None of the candidates directly answered the question; most of the ones who answered it – after several attempts by moderator CNN reporter Anderson Cooper – did so vaguely, usually saying that their messages were for all Americans. Some candidates said efforts to single out an ethnic or racial group were not productive.
Former U.S. Senator Rick Santorum said Hispanics have strong family values and strong faith.
In a post-debate analysis, Gwen Ifill, political analyst on PBS, said the Latino audience member's question to the candidates had gotten no better than a "flat-footed" response.
"Many didn't know what to say," she said, "as far as appealing to the fastest-growing community in this country."
Elizabeth Llorente is Senior Reporter for FoxNews.com, and can be reached at Elizabeth.Llorente@Foxnews.com. Follow her on Twitter @Liz_Llorente.