BY BETH REINHARD AND CASEY WOODS

Foreshadowing a fierce contest for the nation's largest swing state, Republican John McCain and Democrat Barack Obama clashed Tuesday over Cuba in an ongoing foreign policy skirmish played out for Florida's potent Hispanic vote.

Speaking in Miami on Cuban Independence Day, McCain assailed Obama for his willingness to broach talks with the communist regime about democratic reforms, saying it would send ''the worst possible signal.'' Obama struck back a few hours later on CNN, arguing that McCain would continue President Bush's ''failed'' policies.

Even before Obama's televised retort, Democratic rival Hillary Clinton jumped into the fray, clearing her schedule for rallies Wednesday in Miami, Sunrise and Boca Raton that will overlap with Obama's first trip to the state this year. Obama's three-day swing Wednesday-Friday will include mega rallies at 20,000-seat arenas in Tampa and Sunrise and smaller gatherings in Miami and Boca Raton.

McCain's speech at the Sheraton Miami Mart reflected his overall campaign strategy of trying to undermine Obama's credentials on foreign policy, calling his ideas "dangerous.''

''He also wants to sit down unconditionally for a presidential meeting with Raúl Castro,'' said McCain, drawing boos from the hundreds of Cuban-American leaders and Republican activists in the audience. "These steps would send the worst possible signal to Cuba's dictators -- there is no need to undertake fundamental reforms, they can simply wait for a unilateral change in U.S. policy. I believe we should give hope to the Cuban people, not to the Castro regime.''

OBAMA RESPONDS

Obama, ahead of his meeting with the Cuban American National Foundation on Friday, went on CNN to defend his foreign policy. "Now, I know that John McCain likes to characterize this as me immediately having Raúl Castro over for tea. What I've said is that we would set a series of meetings with low-level diplomats, set up some preparation, but that over time I would be willing to meet and talk very directly about what we expect from the Cuban regime.''

For decades, the GOP has rallied Florida's politically influential Cuban-American community against the common enemy of communism. President Bush spoke in Miami on Cuban Independence Day in 2002. So did Ronald Reagan in 1983.

But with growth among immigrants from other Latin American countries, the 2008 election will test the traditional alliance between the Hispanic community in Florida and the Republican Party. Hispanic Democrats now outnumber Hispanic Republicans in the state.

Before and after McCain's speech and Obama's response, their campaigns scrutinized the other side's record for gaffes and inconsistencies. A close review shows both candidates have moved to the right on Cuba over the last few years.

When he ran for the U.S. Senate in 2003, Obama said he supported lifting the trade embargo. Now he only favors ending restrictions on travel and remittances.

McCain said in 2000, when he was running for president, that he would be open to ending the embargo if political prisoners were released. Now he says Cuba must also hold free elections.

McCain was introduced by Roberto Martin Perez, who was imprisoned in Cuba for 28 years. ''You've been making it very clear in this community that you will have nothing to do with the Castro regime, and for that, believe me, Florida will be yours,'' said Cuban-American radio talk-show host Ninoska Pérez-Castellón.

McCain criticized his Democratic rivals for opposing a free-trade agreement with Colombia that he said would benefit American workers and strengthen ties with Latin American allies. Democrats in Congress oppose the pact because of concerns about human-rights abuses in Colombia.

''What is the message you send to the other countries in your hemisphere if you turn down your best friend, the country that's helping you combat the terrible effects of drugs that flow across our southern border?'' McCain asked. "That's the signal the Democrats and Sen. Obama want to send. It's wrong.''

COLOMBIAN SUPPORT

Fabio Andrade, president of the Americas Community Center, brought McCain a bracelet woven in the blue, red and gold colors of Colombia's flag as a symbol of "commitment to Colombian Americans.''

''He is a military person, and in the military it is very important for the people who are on a team to look out for each other and to have each other's back,'' Andrade said. "The main message we got from this meeting is that he will have [Colombia's] back and expects Colombia to watch his.''

The debate centered on Latin America, but spanned the globe, with McCain also criticizing Obama's willingness to speak to other anti-American leaders, like Mahmoud Ahmadinejad of Iran.

''It's dangerous to America's national security if you sit down and give respect and prestige to leaders of countries that are bent on your destruction or the destruction of other countries,'' McCain said.

Obama on CNN said he would meet with Iranian leaders only after "sufficient preparation.''

"John McCain essentially wants to continue George Bush's policies of not talking to leaders we don't like . . .. It has been a failed policy. Iran is stronger now than when George Bush took office."

Miami Herald staff writer Lesley Clark contributed to this story.