MARSHALLTOWN, Iowa — Republican presidential candidate Mitt Romney said Thursday he'll probably deliver a speech explaining the role his Mormon faith plays in his political life, but he argued he's made strong gains among evangelicals despite questions about his religion.

"I have thought about that," Romney said in an interview with The Associated Press. "I haven't made a final decision, but it's probably more likely than not."

During a campaign appearance earlier in the day, Romney was asked about his views on appointing a "God-fearing Mormon" to the Supreme Court. Romney has been asked about such matters frequently in question-and-answer sessions he holds almost daily.

"I'd go after people who will follow the law and I wouldn't apply a religious test either," Romney said.

In the interview, Romney acknowledged the issue crops up often enough that he's pondering dealing with it in a comprehensive manner.

"It's probably too early for something like that," Romney said. "At some point it's more likely than not, but we'll see how things develop."

There is precedent for such a step. When John F. Kennedy sought the presidency in 1960, there was a whispering campaign about his Catholicism, and he largely put the issue to rest by going to Texas to deliver a speech about the role that religion played in his life.

Romney said it's too early to decide what he would say in such a speech, largely because he hasn't made a final decision to deliver such a talk.

In March, a Gallup poll found that 46 percent had a negative opinion of The Church of Jesus Christ of Latter-day Saints. The Southern Baptist Convention, the nation's largest Protestant group, considers the LDS Church a cult, and many other Christian denominations also do not recognize Mormon baptism.

Romney has come under fire from some conservatives — primarily GOP rival Sam Brownback — for switching positions on issues such as abortion and gay rights. Romney said those charges haven't hurt his standing as he competes for the backing of social conservatives, who play a crucial role in Iowa Republican politics.

And Romney was dismissive of the criticism.

"I expect that evangelical Christians who believe in life and family values are going to vote for someone who shares their views and has a real prospect of being nominated by our party and becoming president," Romney told the AP. "The difference between me and Sam Brownback is he has run a uniformly negative campaign."

Romney was clearly annoyed by Brownback's criticism, saying the Kansas senator is alone among the GOP field in going on the attack.

"Virtually all have run positive campaigns, except one," said Romney. "He has run a uniformly negative campaign, which has distorted the truth and been mean-spirited. I think Iowans will reject that."