des moines -- Former Massachusetts Gov. Mitt Romney has fought for months to unite social conservatives behind his bid for the Republican presidential nomination.
But his weekend victory in an Iowa straw poll only underscored the fierce competition he still faces for conservatives who remain wary of the GOP's top White House contenders.
"Clearly, no one has consolidated the conservative vote," said Whit Ayres, a Republican strategist unaligned in the presidential race.
The mock election that Romney won at a state party fundraiser in Ames on Saturday was purely symbolic, and of questionable value as a gauge of Republican voters in Iowa.
Still, the popularity of two rivals seeking to corner the Christian right's support -- former Arkansas Gov. Mike Huckabee and Sen. Sam Brownback of Kansas -- exposed the limits of Romney's appeal among conservatives. Combined, Huckabee and Brownback, who placed second and third, won more votes in the straw poll than Romney did.
Posing a potentially stronger challenge to Romney is former Sen. Fred Thompson of Tennessee, a "Law & Order" television star who has targeted conservatives as his core constituency in the run-up to a formal announcement of his candidacy.
National polls suggest Thompson carries strong appeal with the religious right. He skipped the Ames contest, and plans to campaign in Iowa for the first time Friday at the state fair in Des Moines.
Also in Romney's way is Rudolph W. Giuliani. The former New York mayor has not forsaken social conservatives, even if his support for legalized abortion, gay rights and gun control poses serious difficulties with that group. On a trip across Iowa last week, Giuliani called for steps encouraging adoption as an alternative to abortion.
In Iowa, where Giuliani is to campaign again Wednesday, conservative evangelicals are a potent force in Republican elections, especially when unified behind one candidate in a crowded contest. Iowa's precinct caucuses are scheduled to kick off the 2008 party nomination balloting in five months.
Romney has steadily gained a lead in Iowa Republican polls, but Giuliani remains the front-runner in national surveys. Gary Bauer, a conservative leader who ran for president in 2000, said Giuliani's "problem on values issues will loom larger" once religious conservatives rally behind someone else.
"He only looks formidable because the vote's being split nine different ways," Bauer said.
The field narrowed Sunday evening, when former Wisconsin Gov. Tommy Thompson dropped out of the race, citing his sixth-place finish in Ames.
Romney has banked heavily on Iowa. By spending far more on TV ads here than any other Republican, he has driven up his poll numbers. But, said strategist Ayres, "all of that can change when the other candidates go on the air, or when a candidate as potentially popular as Fred Thompson gets in the race."
Once Thompson is officially in, added former Republican National Committee Chairman Rich Bond, "that's just going to completely reshuffle the deck."
Like Giuliani and Romney, Thompson is no sure bet with religious conservatives, particularly on abortion. In the Senate, he built a solid antiabortion record. But his past statements on the issue and his reported work as a lobbyist fighting federal restrictions on abortion counseling in the early 1990s have raised doubts about his commitment to the cause.
Romney, too, faces challenges on the issue of abortion. When he ran for statewide office in Massachusetts in 1994 and 2002, he said he supported abortion rights, but now he describes himself as "pro-life." On "Fox News Sunday," he faced, as he has many times before, before-and-after videotape of his comments on abortion.
"If there's some people who can't get over the fact that I've become pro-life, that's fine," Romney said. "But I'm not going to apologize for the fact that I am pro-life, and that I was wrong before, in my view, and that I've taken the right course."
Opponents who tried to "bring me down and attack me" by raising the issue, he added, failed to win the Ames straw poll.
"Obviously, they're going to continue to come at me with hammer and tong, but I believe people want to look beyond the attacks and understand what is it that a person stands for," Romney said.
In an appearance Sunday on CBS' "Face the Nation," Huckabee took issue with Romney's switch on abortion.
"I think that Republicans look for a conservative who has had consistency in his principles," Huckabee said. "And there is not going to be any YouTube moments of me saying something substantially different on the sanctity of life" or other issues.
Romney supporters portrayed the Ames results as a sign of progress in building conservative support, even if the outcome was skewed by the refusal of Giuliani, Fred Thompson and Sen. John McCain of Arizona to participate.
Ron Kaufman, a senior Romney advisor, said the candidate's Mormon religion and his leadership of a liberal New England state had posed challenges with the Christian right, and the straw poll proved he could overcome them.
"The big question is, Can he win?" Kaufman said. "And the best way to answer that question is to win things."