Who are they? It seems that reluctance to vote for a Mormon is about the only thing on which many evangelical Protestants and liberal Democrats agree. The former, of course, present a significant stumbling block for Romney and fellow Mormon Jon Huntsman, the former Utah governor and potential presidential candidate, given the number of evangelicals in early caucus and primary states such as Iowa and South Carolina.
Romney was optimistic earlier this year during an interview with CNN's Piers Morgan.
"I can't judge the politics. I don't know the answer to that," he said. "My experience so far, in Massachusetts running as a Mormon guy in a state that's overwhelmingly of other faiths, is it didn't seem to get in my way there. But most people in the country recognize that, in fact, the nation itself was founded on the principle of religious tolerance and freedom."
My interaction with radio callers tells me he is overly optimistic. I've heard from many voters willing to state their hesitancy to vote for a Mormon, including "Sean," a self-described Catholic from Indianapolis.
"I'm in that group that won't vote for a Mormon," he told me. Why? "Because I think it implies poor judgment and critical-thinking skills."
Sean's critique didn't surprise Anthea Butler, a religion professor at the University of Pennsylvania. "Most Americans don't know the basic history and beliefs of their own faith, let alone any of the major religious traditions," Butler told me.
Sean, and those who make up the quarter of the country unwilling to elect a Mormon, believe the followers of Mormonism are insufficiently dubious about their own religion.