DES MOINES, Iowa - Republican presidential candidate Mitt Romney, striving to be the country's first Mormon president, will give a speech this week explaining his faith to voters, his campaign said yesterday.

The decision comes as the former Massachusetts governor's bid to win in Iowa is threatened by former Arkansas Gov. Mike Huckabee.

Exploiting skepticism about Mormonism among some conservative Christians, Huckabee, a onetime Southern Baptist minister, has erased the lead Romney held for months in Iowa and turned the race into a dead heat.

Romney will deliver a speech called "Faith in America" at the George Bush Presidential Library in College Station, Texas, on Thursday, outlining his religious beliefs and how they might impact his administration.

"This speech is an opportunity for Gov. Romney to share his views on religious liberty, the grand tradition religious tolerance has played in the progress of our nation, and how the governor's own faith would inform his presidency if he were elected," Kevin Madden, a campaign spokesman, said in a statement.

Madden stressed that Romney made the decision last week and that the venue doesn't indicate that Bush is endorsing Romney.

The Texas site - and speech itself - recalls the address John F. Kennedy made in Houston as he sought to explain his faith during the 1960 campaign that led to his becoming the first Catholic president.

Romney's Mormon faith has been an issue as he tries to position himself as the candidate of the GOP's family-values voters.

A Pew Research Center poll in September found a quarter of all Republicans - including 36 percent of white evangelical Protestants - said they would be less likely to vote for a Mormon.

In Iowa, religious conservatives play a big role in GOP caucuses. Polls show the race a toss-up there. Just a month ago Romney held a wide lead and Huckabee trailed in the single digits.

Last week, Huckabee sought to exploit Romney's political weaknesses, including his Mormon faith, by running a TV ad in Iowa that emphasizes his own religious beliefs. The ad doesn't mention Romney but clearly targets him.

"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.

But in an interview yesterday on ABC's

This Week

, he took a pass when asked if Mormonism contradicts the central teachings of Christianity.

Romney, for his part, sought Friday to strengthen his own support among religious and social conservatives, meeting with members of the Iowa Christian Alliance in Dubuque, Iowa.

"I am pro-life. I am pro-family," Romney told them. "If I am the president of the United States - and frankly even if I'm not - I will work hard and tirelessly to preserve marriage as an institution."

How he should deal with questions about his faith has divided his political advisers. Some suggested he give a speech touching on his beliefs. Others said discussing his faith would bring too much attention to his religion.

Those backing a speech said privately that Romney would benefit from talking about his religion because Mormons, who are members of the Church of Jesus Christ of Latter-day Saints, pride themselves on the separation of church and state as well as on tolerance for all religions.