Republican rivals Fred Thompson, Mitt Romney and John McCain sought on Friday to become the favorite of anxious social conservatives, each suggesting he offered the best chance of thwarting abortion rights supporter Rudy Giuliani.

"This is not the time to turn our back on the progress we've made on the issues that matter most," McCain, the Arizona senator, told a receptive gathering of "values voters." "I have a record that can be trusted."

Drawing whistles and applause, Mitt Romney said: "We're not going to beat Hillary Clinton by acting like Hillary Clinton." The former Massachusetts governor added: "I'm pro-family on every level from personal to political."

Thompson, who acknowledged last month that he wasn't a regular churchgoer, earned a standing ovation and cheers when he said what he would do immediately after being inaugurated: "I would go into the Oval Office and close the door and pray for the wisdom to know what was right, and I would pray for the strength to do what is right."

Without mentioning Giuliani by name, the trio each made pitches to be the main alternative to the former New York mayor's candidacy. Giuliani's success so far in the GOP nomination race has prompted talk among leading conservatives of possibly backing a third-party candidate.

The thrice-married Republican leads in national popularity polls and has sought common ground with social conservatives despite his support for abortion rights and gay rights. He argues that whether or not people agree with him on the issues, he has the best chance to beat Clinton, the Democratic front-runner.

Campaigning in Florida on Friday, Giuliani said, "What I've found among what you call social conservatives is a great respect for the fact that I'm honest with them and I'm not trying to change all my positions just to fit what somebody wants. What I am able to do is to say to them, 'On the very big issues, on the important issues, we're together. On nine out of 10 issues we agree with each other."'

Giuliani speaks to the group Saturday, as does former Arkansas Gov. Mike Huckabee, a Southern Baptist minister who is favored by Christian evangelicals but whose campaign has made little headway.

As the conference convened, Sen. Sam Brownback of Kansas, another favorite of the religious right, bowed out of the race. Of social conservatives, Brownback said: "I came to them with the cause, but I don't have the resources and the name."

Religious and cultural conservatives make up a significant part of the GOP base but have not yet coalesced around any one candidate. Recent Associated Press-Ipsos polls found roughly one in five conservatives, churchgoers and Christian evangelicals still undecided.

Their leaders have largely rejected Giuliani because of his moderate-to-liberal positions on social issues and view the other three leading candidates as flawed for various reasons.

—Romney, a Mormon from Massachusetts, once backed abortion rights but has reversed himself on that issue and shifted to the right on others during his presidential run.

—McCain angered social conservatives when he called their leaders "agents of intolerance" in 2000. He hasn't been a vocal champion of their core issues even though he has a solidly right-flank voting record.

—Thompson has drawn criticism for conflicting statements on abortion in his Senate races, his lobbying work on behalf of an abortion-rights organization and his opposition to a constitutional amendment banning gay marriage.

Thompson, McCain and Romney are urging social conservatives to put those concerns aside and rally around one of them — or risk a Giuliani nomination.

Thus, all three filled their speeches with frequent references to God as they emphasized their opposition to abortion, their support for marriage between men and women only and their commitment to appoint judges who would not legislate from the bench.

Romney, whose Mormon faith has made some evangelical Christians wary, tried to dismiss the notion that his religion was repelling voters.

"I imagine that one or two of you may have heard that I'm Mormon," he said, drawing chuckles from the friendly crowd. "I understand that some people think that they couldn't support someone of my faith. But I think that's just because they've listened to Harry Reid," he said, referring to the Senate Democratic leader from Nevada, who also is of the same faith.

Romney added: "What I'm really pleased about is that so many people of faith have come to endorse my candidacy and my message."

Thompson, for his part, called himself a consistent conservative during his Senate tenure, adding: "That's who I was then, that's who I am today and that's the kind of president I would be."

McCain, who got a polite reception and then a standing ovation, slapped at all three of his top competitors.

"I'll match my record of defending conservative principles against any other candidate in this race," McCain said, adding that while voters may not always agree with him, "I hope you know I'm not going to con you."