"I'm just not going to go off into evaluating other people's doctrines and faiths. I think that is absolutely not a role for a president," the former Arkansas governor said during a week in which religion has become an important issue in the Republican presidential race, particularly in Iowa.
In recent weeks, Huckabee has moved from the back of the GOP pack in Iowa to challenge longtime leader Romney, who would be the first Mormon president. The race is now a dead heat in the state, with the Iowa caucuses -- the first contest in the nomination fight -- set for Jan. 3. Christian evangelicals, by many estimates, make up anywhere from 30 percent to 50 percent of Republicans who will attend the caucuses.
Huckabee has consolidated the support of influential religious conservatives, primarily by reaching out to a network of pastors across the state. He spoke privately Monday night to several hundred gathered in Des Moines for a conference, the only presidential candidate to do so.
For months, Romney held wide leads in polls in the state, but he also has faced skepticism about his religion. The former Massachusetts governor plans to address his faith in a major speech Thursday in Texas.
On Tuesday, Huckabee sidestepped when asked what he thought about the view of some Christian evangelicals that Mormonism is a cult.
"I don't think it's relevant to the presidency. I really don't," he said. "You know, I get all these questions about somebody else's religion. I only want to address the ones about my own, and I think some of those get a little bit almost unfortunately laborious because, you know, we ought to be talking about education and health care and energy independence and all these other things."
While he said he respects "anybody who practices his faith," Huckabee said what other people believe -- he named Republican rivals Romney,, and Democratic front-runner -- "is theirs to explain, not mine, and I'm not going to."
He also resisted wading into theology when pressed to explain why some evangelicals don't view the Mormon faith as a Christian denomination.
"If I'm invited to be the president of a theological school, that'll be a perfectly appropriate question, but to be the president of the United States, I don't know that that's going to be the most important issue that I'll be facing when I'm sworn in," he said.
Some Christian evangelicals disagree with -- and view as heretical -- the teachings of the Church of Jesus Christ of Latter-day Saints.
Mormons believe that authentic Christianity vanished a century after Jesus and was restored only through Joseph Smith. Considered a prophet by Mormons, Smith revised -- and in his view corrected -- large sections of the Bible in the 19th century. The Mormon scriptures include the Old and New Testaments, but also include books containing Smith's revelations.
The Southern Baptist Convention, the nation's largest Protestant group, sends missionaries to Mormon communities to spread "the true Gospel of Jesus Christ." Other Christian denominations don't recognize Mormon baptism.
Countering, the Mormons say they are badly misunderstood and insist their church is Christian.
As he has risen in polls, Huckabee has emphasized his own faith and in recent weeks has sought to draw subtle distinctions with his rivals by running a TV ad on the issue in the state.
"Faith doesn't just influence me. It really defines me. I don't have to wake up every day wondering what do I need to believe," Huckabee says in the ad. "Let us never sacrifice our principles for anybody's politics. Not now, not ever."