HIALEAH, Florida (Reuters) - Conservative Hispanic activists fear a win by Republican frontrunner Donald Trump in Florida’s presidential nominating contest next week will deal a major setback to efforts to widen the party’s appeal beyond white voters, potentially dooming hopes of retaking the White House from Democrats in 2016. Some of the activists said in interviews they feared a Trump win could prompt many Latino Republicans, angry at his anti-immigrant rhetoric, to stay home on Nov. 8, Election Day, or worse, support the Democratic nominee.  “Sadly, the damage is going to be felt by the Republican Party for years,” said Javier Palomarez, president and CEO of the U.S. Hispanic Chamber of Commerce, of a possible Trump win in Florida on March 15. “This is a turning point,” he said. Trump has dominated opinion polls and early nominating contests, in large part because of his pledge to build a wall along the border with Mexico; his labeling of Mexicans as criminals and rapists; and his accusations that immigrant workers steal American jobs. That kind of talk is well received by many white Republican voters, but not by minorities, polls show.  That's a problem for the party, because while the American electorate has become more diverse in the last three years, Republican support among Hispanic likely voters has shrunk, from 30.6 percent in 2012 to 26 percent in 2015, according to an analysis of Reuters/Ipsos polling data. Meanwhile, Hispanic Democrats grew by 6 percentage points to 59.6 percent. (Graphic: tmsnrt.rs/1Oj9SPi) Trump’s campaign declined to comment, but he has consistently argued he can win the Latino vote, in part because his companies have employed thousands of Hispanics. “They’re incredible people. They’re incredible workers. I love them. I love them,” he said at a debate in February. Much of the establishment wing of the Republican party has thrown its weight behind Florida Senator Marco Rubio, a first-generation Cuban American. Rubio, however, lags Trump by 15 points in polls in Florida and may be forced out of the race if the New York businessman bests him. For Mark Gomez, a 20-year-old Cuban-American student at the University of Miami and a Rubio volunteer, the differences between Rubio’s and Trump’s approaches hit home when earlier this month on Twitter, a Trump supporter called him an “anchor baby.” Gomez was born in the United States of Cuban refugee parents. Immigration critics sometimes use “anchor babies” to describe U.S.-born children of illegal immigrants, usually from Latin America. Immigration groups say the phrase is offensive. Trump, Gomez said, “is just playing into people’s fears.” Rubio has toured Florida’s Latino enclaves in recent weeks, switching easily between Spanish and English at his rallies, while his allied super PAC, or independent fundraising group, has outspent all rivals combined in ads to boost him and erase Trump’s polling lead. Among Rubio’s challenges in besting Trump, however, could be drawing in younger generations of Florida’s Hispanics. Unlike conservatives of the past, who could take the Cuban-American vote in Florida for granted if they aggressively criticized the Castro government in Cuba, candidates are dealing with a new generation that is leaning more heavily to the Democratic Party. A decade ago 64 percent of Cuban registered voters nationwide identified with the Republican party. That’s now down to 47 percent, according to the Pew Research Center. And among young Cubans, from 18 to 49, more than half now identify with or lean toward the Democrats.      “A lot of those Cubans who come from the island, that resentment, that pain, that hurt has really driven how they’ve reacted politically. Our generation is a generation removed from that in a lot of ways,” said Gabriel Pendas, 33, of Miami. He called Rubio “so outdated from how a lot of people feel.”  Following Mitt Romney’s defeat as the Republican party’s presidential nominee in 2012, in which he received just 27 percent of the Hispanic vote nationwide, the Republican National Committee underwent an extensive and painful self-examination  to determine the root causes of its failure. One thing was clear from the autopsy: The party needed to expand a voter base skewing too white and too old. The hope among party leaders, like Republican National Committee Chairman Reince Preibus, was that a young, dynamic field of candidates like Rubio, Texas Senator Ted Cruz, and others, would position the party well to reclaim some share of Latino vote from the Democrats. Rubio stood central to those hopes. Young, telegenic, bilingual, and armed with a compelling backstory, he seemed made-to-order. “Rubio’s tone, his aspirational message, his shared language and culture, makes him an ideal candidate,” said Daniel Garza, director of the LIBRE Institute in Miami, a conservative Hispanic advocacy group.  But Trump, as he has done so often during this election season, took a wrecking ball to those plans.  His hardline immigration stance forced many of his rivals - including Cruz - to adopt a harsher approach on immigration, while leaving others such as former Florida Governor Jeb Bush, who has dropped out of the race, adrift.  “We’ve lost an incredible opportunity,” said Alfonso Aguilar, president of the Latino Partnership for Conservative Principles, referring to Trump’s front-runner status. Addressing a rally on Wednesday night in Hialeah, home to the largest number of Cubans outside of Cuba, Rubio spoke in both English and Spanish and urged supporters to “come out and vote in massive numbers.” Awaiting Rubio at the rally, Cuban-born Ahmed Martel, 45,  was asked what he would do if Trump, not Rubio, was the party’s nominee in the fall. “I won’t vote,” Martel said. “I can’t vote for him.”  (Additional reporting by Grant Smith and Maurice Tamman; Editing by Richard Valdmanis and Ross Colvin) This article was funded in part by SAP. It was independently created by the Reuters editorial staff. SAP had no editorial involvement in its creation or production.