WASHINGTON — Many Americans are uncomfortable with the Mormon religion — yet Mitt Romney, who is Mormon, is the clear frontrunner for the 2012 Republican presidential nomination, according to a new Quinnipiac University poll released Wednesday.

The nationwide survey asked voters to rate their comfort levels with the faiths of presidential candidates: Eighty-three percent said they were entirely or somewhat comfortable with Roman Catholics, 80 percent with Jews, 67 percent with evangelical Christians and 60 percent with Mormons.

But 36 percent said they were uncomfortable with Mormons. Only atheists and Muslims drew higher discomfort ratings.

In addition, 45 percent said they had favorable opinions of the Mormon religion, with 32 percent saying their views were unfavorable.

Romney, a former governor of Massachusetts, addressed his religion when he ran for president in 2008, saying in a December 2007 speech, “I do not define my candidacy by my religion. A person should not be elected because of his faith nor rejected because of his faith.”

Another Mormon, former Utah Gov. Jon Huntsman, could soon join Romney in the 2012 race.

They are likely to have to address the issue of their faith openly.

“The fact that less than half of voters have a favorable view of the religion is likely to be a political issue that Governor Mitt Romney, and should his campaign catch on, Governor Jon Huntsman, will have to deal with as they pursue the White House,” said Peter Brown, assistant director of the Quinnipiac University Polling Institute.

Among self-identified Republicans, Romney has a big lead over other potential GOP candidates. His 25 percent topped former Alaska Gov. Sarah Palin, at 15 percent. She has not said whether she will run.