KISSIMMEE — If Hillary Clinton wins Florida — all but sending her to the White House — one of the major reasons will be a dramatic outpouring of Hispanic voters like Greta Gomez determined to deliver a thundering rebuke to Donald Trump.

"Trump is very scary," Gomez said as she waited in line Sunday to get into a rally featuring President Barack Obama in this heavily Hispanic city. "He's a xenophobe. He's racist. He's a misogynist. He's not the kind of man who should be president."

The 34-year-old English teacher moved to Kissimmee from Puerto Rico this summer and said she was proud to cast her first vote. "Even my students who can't vote, they are saying they wish they could just because they are also scared of Trump."

Hispanics across the nation are voting in record numbers, giving a critical boost to Clinton.

Through Saturday, 565,000 Hispanics had completed early in-person voting in Florida, a 100 percent increase over 2012, according to an analysis by Dan Smith, a University of Florida political science professor who tracks voting data.

Including absentee ballots, 911,000 Hispanics have voted — more than a third of whom did not vote in 2012. "We're witnessing explosive early voting turnout of Hispanics — both those newly registered to vote as well as those who sat on the sidelines in 2012," Smith said.

If the Hispanic vote proves decisive, Trump's fate could have been sealed on the day he announced his candidacy, descending an escalator at Trump Tower in New York and launching into an attack on illegal immigration and Mexican "rapists" and drug smugglers. He has vowed to build a huge wall and make Mexico pay for it.

Mainstream Republicans who have pressed the party to address its heavy reliance on white voters, whose overall share of the electorate continues to shrink, are alarmed. While the party has made attempts at Hispanic outreach this election, Trump has done little. He has not run a single Spanish-language TV ad.

"Our faithful Republican friends have been so attached to the days of Leave It to Beaver that they have ignored each true friend telling them 'Our world has changed and we better adjust because this is serious.' But they told us, 'we know better, we know best,' " Mike Fernandez, a Cuban-American billionaire and Republican donor from Miami who is supporting Clinton, wrote in an email Sunday to other Republicans.

"Unless there is a complete restructuring of the Republican leadership structure, we will die from an infection which was ignored," Fernandez wrote in the message titled "A gangrene named Trump."

The Hispanic population in Florida continues to boom — with much of the growth in Central Florida — as well as across the country. But voter participation has lagged in past elections.

The reasons vary, including a younger population that across all demographics does not vote as much, socioeconomics and a feeling that politics won't make a difference in their lives.

"It's frustrating," said Frank Sharry, executive director of America's Voice, an activist group.

Sharry credits Trump for the swell but also a steady focus on mobilizing the Hispanic community, encouraging people to engage politically and to vote. The effort got a boost this year with a $15 million investment from George Soros and other liberal donors, the bulk of the money going to Florida, Colorado and Nevada. Soros has also funded an effort tailored to Florida's Puerto Rican community.

A robocall to Florida voters from People for the American Way asks in Spanish, "Have you made a plan to vote yet? We need to make sure to vote against Trump and his hate. Your vote matters and your community is counting on you."

"One of the key story lines coming out of this election is likely to be that Donald Trump's insulting Latinos as part of his strategy to mobilize angry white voters," Sharry said. "But it backfired."

The race remains tight but if Hispanics help deliver Florida for Clinton, she will have effectively blocked Trump's path. Thousands of Puerto Ricans turned out to see Obama in Kissimmee on Sunday.

"When you vote, we cannot lose," said Obama, who got 60 percent of the Hispanic vote in Florida in 2012, helping him eke out a win by less than 1 percentage point. Clinton is currently matching Obama's support in Florida, according to a poll released last week by Univision. Trump was trailing what Mitt Romney achieved four years ago by 9 points.

"When you vote, we reject fear. When you vote, we embrace hope," Obama said. "Choose hope. Choose hope. Choose hope …"

Rosa Agosto, 39, said she always votes, "but this year is really important for us Latinos to make sure Trump does not become president. He doesn't have the values of our nation. Even though I'm not Mexican, I'm Puerto Rican, he speaks for all of us when he says those things. I have three daughters and I don't think he should be talking about women the way he talks."

Agosto encouraged her daughter, a student at the University of South Florida, to cast her first vote for Clinton.

"Trump is the difference," said Jennifer Franco, 43, explaining why she was voting for Clinton. "If his approach to the Latino community was different, maybe he would have our vote. But he's trashing us. I've been in the U.S. a long time. I've worked all my life, and the way he expresses himself about Latinos, it's ridiculous. He's just a racist."

Correction: Donald Trump descended an escalator at Trump Tower the day he announced his candidacy for president. An earlier version of this story was incorrect.