On the morning that two hijacked airliners slammed into the World Trade Center towers, Antonio Adger decided to leave New York City for good. The next day, Sept. 12, 2001, he packed his belongings, rented a U-Haul and started driving from Brooklyn to a place just short of where land meets sea in sunny Central Florida.

Adger liked the blazing heat and how people on the street looked him in the eye, smiled and said hello. It was nothing like home, he said, except in one important sense: People he met were Spanish-speaking Puerto Ricans, like himself. Many had left New York and Puerto Rico to settle in Orlando, Tampa and Lakeland.

"When Puerto Ricans meet other Puerto Ricans, they bond," Adger said recently at his apartment in Tampa.

He joined what Puerto Rican activists are calling "the Florida phenomenon," a migration to the heart of the Sunshine State along the snaking Interstate 4 corridor. Drawn by cheaper housing, better schools and the tropical climate, Puerto Ricans are helping to remake Central Florida culturally -- and, Democrats hope, politically.

Angelo Falcon, a senior policy analyst for the Puerto Rican Legal Defense and Education Fund in New York, said the movement of Puerto Ricans, who tend to vote for Democrats, could "offset the Cuban vote," which almost uniformly has gone to conservatives who promise to continue isolating the communist government of Fidel Castro.

If the migration continues at its current pace, Puerto Ricans -- along with Dominicans and Colombians, who are also migrating to Florida in droves -- could become the more dominant force in Florida's landscape.

According to the census, 241,000 Puerto Ricans were living in Florida in 1990. Ten years later, the number was 482,000. This year, the Puerto Rican Legal Defense and Education Fund and the Washington-based Puerto Rico Federal Affairs Administration estimated that more than 650,000 Puerto Ricans live in the state, most of them in Central Florida.

Florida's Cuban population, by comparison, was 833,000, according to the 2000 Census. Conservative Cubans helped George W. Bush win Florida that year by 537 votes. The state has an additional 1 million Latinos who are neither Puerto Rican nor Cuban.

"That group of voters, this emerging non-Cuban vote that is centered in Orlando and Tampa and to a certain extent South Florida, is becoming one of the most important battlegrounds in Florida," said Sergio Bendixen, a pollster who specializes in monitoring the state's Latino vote.

Latino voters' party affiliations may be less rigid than commonly perceived, warned Arturo Vargas, executive director of the National Association of Latino Elected and Appointed Officials, during a NALEO conference in Washington last month. Puerto Ricans in Central Florida, Vargas said, voted overwhelmingly for Florida's Republican governor, Jeb Bush, in 2002.

But Leobardo F. Estrada, a demographer at the University of California at Los Angeles who shared a podium with Vargas at the conference, said, "The tensions are real."

"The Cubans have dominated the local political scene for so long, and are clearly the most powerful group," Estrada said. "But other [Latino] groups are bent differently. They want people to stop talking about Cuba and start talking about issues.

"The further you are from Dade County and Miami, the stronger the anti-Cuban sentiment. By the time you get to Tallahassee, you hear people say, 'Don't believe what you hear in South Florida.' "

In the 1950s, Puerto Ricans were the Latin face of New York, whereas the Cuban community barely existed. They sparked the Latino civil rights movement on the East Coast after the 1964 Civil Rights Act. "Nuyoricans," as New York Puerto Ricans are called, inspired the play "West Side Story" and produced two current pop icons, singers Jennifer Lopez and Marc Anthony.

Puerto Ricans began leaving New York and their native island for Florida in the 1970s. Chuck Dunnick, an Osceola County commissioner who recently traveled to Puerto Rico to promote business relations with Central Florida, said the developers of two huge apartment buildings in Orange County brought "people in from the island by the busload."

"Once the relocation started, aunt and uncle would move over, brother and sister," Dunnick said.

In Queens, Hiram Monserrate, a Democrat and New York city councilman, watched family and friends move to Central Florida starting in the early 1990s, then picking up steam in 2000.

An uncle keeps calling him from Florida and saying, " 'You should come here and help us organize,' " Monserrate says. He has promised to go in August and help get out the vote for Sen. John F. Kerry (D-Mass.) in the presidential campaign.

"When you look at the 2000 election, which was decided by a few hundred votes, there are a lot more Puerto Ricans living there now . . . and it could make a difference," Monserrate said.

Whether Puerto Ricans can claim the Cubans' electoral thunder remains to be seen. Cubans in the Miami area are highly organized and motivated. Cuban Americans made up roughly 65 percent of Florida's 660,000 Latino voters in 2002 -- even though they were only 31 percent of the state's Latino population, according to the census. With the influx of non-Cuban Latinos, Bendixen and others are predicting that the Cuban vote ratio will drop to 50 percent.

In Central Florida, some people seeking to register Puerto Ricans to vote have complained that apathy is a problem, especially among new arrivals from the island.

But apathy can be overcome, said Zulma Velez-Estrada, the Florida state manager of the Que Nada Nos Detenga -- Let Nothing Stop Us -- voter registration project for the Puerto Rico Federal Affairs Administration.

More than 38,000 Hispanics have been registered statewide since December, Velez-Estrada said. The Florida voter registration campaign "is the most successful campaign of the 13 regional offices in the U.S.," she said, but she would not disclose how numbers broke down along party lines, saying that the Puerto Rico agency is nonpartisan.

It is hard to determine how they will vote, said Mari Carmen Aponte, the agency's executive director. Former vice president Al Gore "won Osceola County and Orange County, the first time a Democrat has done that in 20 or 30 years," she said.

Aponte said it was difficult to determine the impact of the Latino vote because the election commission does not break down votes by ethnicity, and because exit poll officials did not take the national origin of voters into account.

In the 2002 election, Gov. Bush campaigned in Orlando and Tampa, delivering speeches in flawless Spanish, promising jobs and better schools -- and won an estimated 55 percent of the area's non-Cuban Hispanic vote, Bendixen said. When Bush returned a few months ago to campaign for his brother's reelection, Orlando lawyer Luis Gomez, a Democrat, wondered how responsive Puerto Ricans will be to the governor this time.

"He hasn't delivered," Gomez said. "You run into the lower spectrum of the economy here, people who work for $7 or $8 an hour. The issues here are education and jobs."

Edison Denizard is less interested in politics than in fulfilling the dream of his parents, who migrated from Puerto Rico to the mainland because "they wanted a better life for me and my sister," Denizard said.

The family moved to Orlando seven years ago, when Denizard was 13. "I didn't know how the situation was going to be," he said, but he could not believe what happened when he entered high school: "My friends spoke the Spanish language. Even though I didn't speak English, they would teach me."

At the gym where he works at an entry-level job, he could hear the steely ping of weights being lifted and dropped, and the voice of a personal trainer shouting to a client, "Vamos . . . uno, dos, tres, cuatro!"

When Denizard goes to the Florida Mall on South Orange Blossom Trail, he runs into other Puerto Ricans working behind retail counters, mixing salads, hawking cell phones. On the way there, he listens to WONQ radio, which competes for listeners with at least five other Spanish-language stations.

Adger said he was not moving back to New York. "My family lives in New York and they ask me to come visit, and the thought of it gives me anxiety," he said.

"I'm used to this Florida living," he said, "and I love it."

Nidza Vazquez of the Puerto Rico Federal Affairs Administration prepares for a voter registration drive in Kissimmee.Democrat Ana Maria Mendez, right, talks with Marcia Garcia at a Latino store in Kissimmee, as Mendez sought signatures to put herself on the ballot.