Republican presidential candidate Newt Gingrich on Wednesday ridiculed rival Mitt Romney's call for self-deportation of illegal immigrants as an "Obama-level fantasy" that would be inhumane to long-established families living in America.

The former House speaker ripped that part of Romney's immigration policy during a forum Wednesday with the Spanish-language network Univision. The interviewer also asked sharp questions about Gingrich's marital history.

Gingrich laughed at the idea of self-deportation and said it wouldn't work.

During a debate earlier this week, Romney said he favors self-deportation over policies that would require the federal government to round up millions of illegal immigrants and send them back to their home countries. Advocates of Romney's approach argue that illegal immigration can be curbed by denying public benefits to them, forcing them to leave the United States on their own.

"You have to live in a world of Swiss bank accounts and Cayman Island accounts and automatically $20 million income for no work to have some fantasy this far from reality," Gingrich said, alluding to details in Romney's income tax returns made public on Tuesday. "For Romney to believe that somebody's grandmother is going to be so cut off that she is going to self-deport, I mean this is an Obama-level fantasy."

But Gingrich's campaign has spoken of the self-deportation policy he ridiculed Wednesday.

Romney's campaign directed reporters to past comments by Gingrich spokesman R.C. Hammond, who said that only a small percent of illegal immigrants would likely be allowed to stay in the U.S. under Gingrich's plan. Hammond went on to say that the vast majority of them would likely "self-deport."

At the forum, Gingrich spoke instead about border control and establishing a guest-worker program to better manage the influx of immigrants. Gingrich said he favors a path to citizenship for illegal immigrant children who serve in the military but not for simply completing college.

As to communist Cuba, not far off Florida's southern shore, Gingrich said he would be open to using everything up to covert operations to replace stalwart Fidel Castro's regime. "Hands off Cuba, that's baloney," he said. "The people of Cuba deserve freedom."

Florida is home to many Hispanics of Puerto Rican or Cuban descent and who view immigration policy as a priority. Thirteen percent of the state's registered voters are Hispanic.

While the questions were mostly about Hispanic concerns, moderator Jorge Ramos asked Gingrich whether it was hypocritical for him to criticize then-President Bill Clinton and pursue his impeachment in the 1990s when Gingrich was also being unfaithful to his second wife.

Gingrich snapped at the premise of the question and said it was Clinton's false testimony under oath that bothered him most.

"The fact is I've been through two divorces. I've been deposed both times under oath. Both times I told the truth in the deposition," Gingrich said. "I have never lied under oath. I have never committed perjury."