What do Mitt Romney and Jon Huntsman have to do to convince voters they would not force Americans into polygamy, ban alcohol, or impose other social conditions some people (often wrongly) associate with the Mormon faith? A Gallup poll released this week shows that 22 percent of Americans would not vote for a Mormon, even if that candidate were running in the voters’ own parties. The percentage is not statistically much different from when Gallup interviewed voters in 1967 (when 17 percent said they would not vote for a Mormon). But it’s notable that the number of Mormon-phobes spiked to 24 percent in 2007, as Romney was making his first run for president, and is back up to 22 percent now that Romney and Huntsman are running. [Check out political cartoons about the 2012 GOP field.]

If 22 percent sounds low, it’s not: With all the other reasons someone might decide not to vote for a candidates, and with the country still as closely divided as it is, candidates can’t afford to write off 22 percent of the vote before even getting into substantive debates with the rest of the field. And the number—especially when compared to Gallup statistics about other categories of people—suggests the problem is deeper. It may not be that 22 percent of voters won’t cast a ballot for a Mormon; it may only be that 22 percent will admit to it.

The same Gallup poll showed that just five percent of voters would not for an African-American for president; six percent would not vote for a woman, and nine percent won’t cast a ballot for a Jewish person. The fact that the country only recently got its first African-American president (actually, mixed-race president, usually identified with his African father’s heritage)—and that a sizable chunk of the country refuses to believe he is even American, but rather, "other"—suggests that maybe people aren’t being truthful. And if just a handful of voters are opposed to a female or Jewish president, logic suggests we would have had one by now. [See a slide show of GOP 2012 contenders.]

There are only two groups which fare poorer than Mormons in the Gallup poll: gays and lesbians (32 percent of voters won’t elect one president) and atheists (49 percent can’t accept the idea of one as president). The numbers may show that these are the groups which still have serious barriers to overcome before advancing in politics. Or it may just mean these are the groups for whom it is still socially acceptable to shun. [Vote now: Does Romney’s “I’m also unemployed” joke mean he’s out of touch?]

Romney, in the Republican debate in New Hampshire last week, was at his most eloquent when he extolled the American tradition of plurality and freedom of religion (this in the context of being asked if Muslims could serve in his administration. Gallup did not query voters about Muslim presidential candidates.). The public, it seems, has yet to catch up.

