Fred Thompson is the Republican most likely to beat abortion-rights supporter Rudy Giuliani, the National Right to Life Committee said Tuesday, announcing its endorsement of the former Tennessee senator for president.

The nod by the prominent anti-abortion group could boost the former Tennessee senator's lackluster campaign -- and it comes amid a spate of other conservative religious groups and personalities backing other Republicans.

Republican Mike Huckabee on Thursday gained the endorsement of conservative activist Donald Wildmon, who has led national boycotts against corporations over social policies and once accused Mighty Mouse of teaching children to snort cocaine.

Wildmon, founder of the American Family Association and a retired United Methodist minister in Tupelo, Miss., announced his support last week. Recently, televangelist Pat Robertson backed Rudy Giuliani and Kansas Sen. Sam Brownback endorsed Arizona Sen. John McCain. Moral Majority co-founder Paul Weyrich has announced support for Mitt Romney.

"While there are various polls, and some are up-and-down, the overwhelming consensus has been that he is best-positioned to top pro-abortion candidate Rudy Giuliani for the Republican nomination," the group's executive director, David N. O'Steen, said at a Washington news conference.

By emphasizing Thompson's political potential -- he ranks second behind former New York Mayor Giuliani in national Republican polls -- the anti-abortion group played down its own differences with Thompson.

Thompson has been at odds with the group because he doesn't support a federal constitutional amendment outlawing abortion, a long-standing party platform plank; because he has called the Terri Schiavo right-to-die case a family matter, and because he backed campaign finance regulations that the group considers a restriction of free speech.

The group also considered candidates' voting records and their stances on various issues, O'Steen said. Giuliani has promised to appoint Supreme Court justices who take a conservative view of abortion, but O'Steen said the group could not overlook Giuliani's support for a woman's right to choose.

He contended that the group's endorsement carries more weight than endorsements by other conservatives in recent weeks.

"This is an endorsement by an organization representing groups throughout the country, 3,000 chapters, and it just can't be compared to individual endorsements," O'Steen said.