The close, volatile Republican presidential campaign exploded in Miami on Wednesday as Newt Gingrich pulled a controversial Spanish-language immigration ad after Sen. Marco Rubio bashed it as out of bounds.

The radio ad, featuring a snippet of a Fidel Castro line, described Mitt Romney as “anti-immigrant’’ for his hardline stances, which mirror those of Rubio and many Republican leaders.

“This kind of language is more than just unfortunate. It’s inaccurate, inflammatory, and doesn’t belong in this campaign,’’ Rubio, who is neutral in the race, told The Miami Herald when asked about the ad. “The truth is that neither of these two men is anti-immigrant,’’ Rubio said. “Both are pro-legal immigration and both have positive messages that play well in the Hispanic community.’’

The unexpected criticism from the nation’s leading Hispanic Republican figure underscored the difficulties of campaigning on immigration in Miami-Dade’s Cuban exile community, which accounts for just under three-quarters of the Republican vote in the largest county of the nation’s largest swing state.

A new poll of Florida Latinos shows Gingrich losing badly to Romney. And both trail President Barack Obama by double digits, although Gingrich does worse among Hispanics against the incumbent than Romney. Two polls released Wednesday showed both essentially tied among all voters.

After Rubio’s criticism, Gingrich’s campaign said it would pull the ad out of “respect’’ for Rubio, whom both candidates would love to have as a running mate. His campaign then announced it would edit out the “anti-immigrant’’ line and re-run the ad.

Gingrich earlier defended the ad’s language in an interview with a Miami TV station. Gingrich specifically took exception with Romney’s call at a Monday debate for people to deport themselves if they’re here illegally.

“I think he’s amazingly insensitive to the realities of the immigrant community — his whole concept of self-deportation,’’ Gingrich said. “I’ve not met anyone who thinks it’s in touch with reality. People aren’t going to self-deport.’’

But his own spokesman had told a New Hampshire newspaper that, as a consequence of Gingrich’s immigration plan, “it’s likely the vast majority of them [illegal immigrants] would self-deport.’’

Romney, too, found himself the target of his own words on the Florida campaign trail, where he has attacked Gingrich as an “influence peddler’’ because he was paid as a consultant for mortgage giant Freddie Mac, implicated in the housing crash and foreclosure crisis gripping one in every 360 Florida homes.

Turns out, a few Romney campaign advisors were lobbyists for Fannie Mae and Freddie Mac, some of whom were paid to fight reform efforts, according to The Associated Press and the Daily Caller conservative news website.

Also, AP and the Democratic group American Bridge 21st Century pointed out that one of Romney’s investments yielded $500,000 from Fannie Mae. And CNN reported that Romney was a “distinguished panelist’’ at a Fannie Mae Foundation housing conference in 2004 — just as the housing bubble started to inflate.