WASHINGTON — When Harry Reid becomes Senate majority leader next year, he will be the most powerful Mormon in Washington.

But that reign could be short-lived if Massachusetts Gov. Mitt Romney makes a bid for the presidency in 2008 and wins. Romney is considering a run in what is expected to be a wide-open field.

Reid is a Democrat from Nevada, and Romney is a Republican. Though they have chosen different political stripes, they are bonded in a faith whose leaders encourage members to become active in public life.

Mormons are heeding the call. Typically conservative, they are more politically active than average Americans, according to a recent study. And the 15 Mormons in Congress is a slightly greater representation than the religious group's percentage of the general population.

"From the pulpit, they talk about the importance of being involved in the community, being involved in politics," said Dean Heller, a Mormon who was just elected to represent Nevada in the House. "They want members of the church to be integrated into society."

The Church of Jesus Christ of Latter-day Saints, as the church is officially called, believes the nation's founders were men of God and that the U.S. Constitution was divinely inspired.

But as politically active as Mormons may be, their faith is largely misunderstood by most Americans.

Some evangelical Christians consider the faith a cult, and 35 percent of Americans say they would not vote for a Mormon for president, according to a recent poll.

That presents a particular challenge for Romney, who so far has steered clear of any public discussion about his religion.

"Because religion matters in politics, it represents opportunities and challenges for candidates," said John Green, at the Pew Forum on Religion and Public Life. "Candidates have to be very cautious when it comes to talking about their faith."

A Time magazine story set to hit the newsstands next week features an article titled "Can a Mormon be president?"

Quin Monson, a political science professor at Brigham Young University in Provo, Utah, says Romney's faith would likely matter to only a minority of voters.

"If a Mormon can be elected as governor of Massachusetts and a Mormon can be Senate majority leader, certainly a Mormon can be president," he said.

A religious minority, Mormons represent less than 2 percent of the American population with 5.5 million members across the country. The church, which claims a total of 12 million members, is one of the fastest-growing faiths in the world.

Roughly 80 percent of Americans consider themselves Christians, with Protestants making up about half of that group. About a quarter are Catholic.