By Carroll Doherty, Associate Director, Pew Research Center. Special to the New York Times.  For more debate on Mormon candidates in the 2012 election click here.

Overall, being a Mormon is hardly an asset for presidential candidates, but it is not a deal-breaker for most Americans. A quarter of Americans say they would be less likely to support a presidential candidate who is Mormon, while 68 percent say it would not make a difference. For perspective, about the same number say they would be less likely to vote for a candidate who has used marijuana in the past.

But an important group within the Republican base, white evangelical Protestants, is more uncomfortable with the idea of a Mormon candidate than are other Republicans. Among all Republicans and Republican-leaning independents, 31 percent of white evangelicals say they would be less likely to vote for a Mormon; that compares with 15 percent of other Republicans, according to a May survey. This gap is as large as it was four years ago.

At that time, our polling found that white evangelical Protestants were more likely than non-evangelical white Protestants to view the Mormon religion as very different from their own. And just 40 percent of all white evangelicals viewed Mormons as Christians; far more non-evangelical white Protestants and Catholics said that Mormons were Christians.

These findings have potentially troubling implications for Jon Huntsman and Mitt Romney, particularly when one considers the G.O.P. primary landscape. Exit polls from 2008 show that 60 percent of those who voted in the G.O.P. Iowa caucuses, and an identical percentage of Republican voters in the South Carolina primary, were evangelicals.