Sen. Orrin Hatch, also a Republican and a Utah Mormon, ran for the GOP nomination in 2000 and lost to George W. Bush, an evangelical. Again, it was said that his faith didn't help him in the primaries.

"I was hoping to expose and eliminate some of the prejudice against Mormons, and I think we made some headway," Hatch said in a telephone interview. "But there is still a little bit out there."

To tackle it, Hatch continued, Romney -- who placed an impressive second in the Southern Republican Leadership Conference straw poll in March -- will need to shift the focus away from religious differences and toward the similarities between himself and conservative Christians, especially on moral issues. "Mormon values on policy questions are much in line with the Christian right than most people know," Hatch said.

Still, Romney hails from a church that shares conservative positions on abortion, gay marriage and stem cell research, to name a few. The shared positions on social issues, political observers say, may be the ultimate key to winning over Christian voters who may be leery about his church affiliation.

What's more, Romney easily won two terms in heavily Catholic -- and Democratic -- Massachusetts, and has proven his ability to transcend the "Mormon candidate" label.

"I am guessing that my kind of people are going to come down on the side of culture wars and would be willing to go for a Mormon," said Richard Mouw, president of Fuller Theological Seminary, and a participant in Mormon-evangelical dialogue. "My guess is that just as evangelicals have toned down the rhetoric against Catholics in recent years because of similarities on social agenda questions, in this case they are going to side with Romney if he comes across as champion of the evangelical social agenda."

Some believe Romney's Mormonism may actually help him with voters.

"The people whose objection to Mormonism is deep rooted, who consider Mormonism a cult -- no," they won't vote for Romney, said Sen. Bob Bennett of Utah, who also is a Mormon. "On the other hand, people who say well, `Y'all believe in Jesus Christ,' is an indication that that group of people is more than willing to put it aside."

Gregory Johnson is an evangelical pastor and former Mormon who heads Standing Together, a group that promotes Mormon-Christian understanding. In May, he spoke before a group of evangelical pastors in Massachusetts who were happy with Romney's pro-life, anti-gay marriage stands. One pastor told him, "Mitt Romney is as evangelical as any evangelical governor I would hope we could have," he recalled.

But Johnson thinks common issues may not be enough for Romney and Christian conservatives to find common ground. "If you put him side-by-side with another candidate who is an evangelical or a Protestant, I just feel Christian conservatives will vote for their own kind."