By Ed Stoddard

WASHINGTON (Reuters) - Former Massachusetts Gov. Mitt Romney narrowly won a Republican presidential straw poll of Christian conservatives on Saturday, while Rudy Giuliani's persuaded few to look past his support of abortion rights.

The poll at a summit of self-styled values voters was largely symbolic but highlighted the continuing failure of ardent anti-abortion social conservatives to rally behind a single Republican candidate in the 2008 White House race.

Romney took 27.6 percent of almost 6,000 votes cast, just ahead of Mike Huckabee, the folksy former governor of Arkansas, who gained 27.1 percent at the conference organized by the Family Research Council.

Maverick Texas congressman Ron Paul was third with almost 15 percent while former Tennessee Senator Fred Thompson got under 10 percent, a major disappointment for his campaign.

Giuliani was eighth with 107 votes -- under two percent.

The victory was a lift for Romney, struggling to overcome the distrust and hostility that many evangelical Christians feel toward his Mormon faith.

Romney appears to have been making inroads among religious conservatives as he portrays himself as a committed opponent of abortion, despite his relatively recent conversion to their cause. He told the gathering on Friday night that he would be a "pro-life president."

In his speech on Saturday, Giuliani appealed to his audience to look beyond his support for abortion rights and focus on shared values, such as fighting crime and his vow to relentlessly pursue the war on terror.

"I truly believe that what unites us is greater than any of the things which divide us," Giuliani, a former New York mayor, said to the crowd of mostly white evangelical Protestants who comprise a key segment of the Republican base.

Stridently anti-abortion and anti-gay rights, this movement known as the "religious right" has watched with dismay as Giuliani, who shot to national prominence after the September 11 attacks in 2001, grabbed the lead in the race for the Republican 2008 presidential nomination.

Some have spoken of backing a third party candidate to fly their anti-abortion banner should he become the nominee.

Opposition to abortion has become an almost sacred Republican plank because of the religious right's influence but Giuliani threatens to break that taboo.

The thrice-married Giuliani, a Roman Catholic who also supports gay rights, dismissed charges that he was an "activist for liberal causes" and told the crowd that Christianity was a religion of inclusion in a speech that drew warm applause but no thunderous ovations.

Saying he felt his faith deeply but privately, Giuliani stressed his record of reducing crime in New York, reiterated his staunch support for Israel and said that victory was the only option in the war on terror.

Giuliani also told them he would appoint conservative justices to the U.S. Supreme Court -- a key policy plank since the Holy Grail of the social conservative cause is getting a bench that will overturn the 1973 Roe v. Wade decision granting women a constitutional right to an abortion.

Giuliani also pledged to work to increase adoptions and decrease abortions -- a stance which hardliners, who say they could never bring themselves to support a pro-choice candidate, regard as far too soft.

"The party has always been a big tent but it's not that big a tent," said Michael Scully, a Romney supporter.

Copyright 2007 Reuters Limited.