Latinos are projected to make up 11.9% of eligible U.S. voters in this year’s presidential election and could sway outcomes in key swing states like Colorado and Nevada, according to a Pew Research Center study released Tuesday.

Interviews with Florida Hispanic Republicans suggest that while Mr. Trump benefits from pockets of support, many regard him with unease, or even hostility. Some said they worry he was pushing other GOP candidates such as Florida Sen. Marco Rubio to adopt harsh rhetoric and more-extreme positions on immigration and other issues.

“Everyone is fed up with politicians, and I can see how he appeals to that audience,” said Nicole Gomez, the 31-year-old president of the North Dade Republican Club in Miami. But “he really exploits that visceral anger” and “his whole demeanor is very repulsive.”

Mr. Trump has repeatedly dismissed concerns about his standing with Latino voters, saying he has a great relationship with them and believes he will win their support because of his ability to create jobs.