Prominent conservative leaders want their rank and file to quickly get behind a single presidential candidate — Rick Santorum now seems the likeliest — fearful that persistent splits will help Mitt Romney win the Republican nomination.

“While no political candidate, or human being for that matter, is perfect, Rick Santorum’s baggage contains his clothes,” CatholicVote.org president Brian Burch said Thursday, after Santorum’s virtual tie with Romney in Iowa won the support of the 600,000-member online organization.

“Republicans hoping to win back the White House in November must unite behind the candidate most dedicated to the foundational issues of faith, family and freedom.”

Romney narrowly won the Iowa caucuses when conservative voters split their support among several challengers, and the worry is that the same thing will happen in South Carolina, Florida and beyond if Rick Santorum, Newt Gingrich and Rick Perry all stay in the race.

“Conservatives are still divided among a number of different candidates, but the field is winnowing,” said former Republican presidential candidate Gary Bauer. And, he said: “I certainly think that Senator Santorum is in a good position to inherit a lot of that support.”

In the afterglow of Santorum’s unexpectedly narrow loss to Romney in Iowa, leaders on the right who have been scarcely engaged in the rollicking Republican contest began buzzing about the prospect of endorsing the former Pennsylvania senator with the solid conservative credentials — or someone else such as Gingrich who has deep conservative roots.

To discuss how to proceed, some of those leaders have set up meetings from Washington to Texas before the Jan. 21 South Carolina primary. That vote could prove pivotal, given that the Republicans who have won the state for decades have eventually become the party’s nominees.

“There is movement, even members of Congress who are weighing this now who are looking to make a move,” said Family Research Council President Tony Perkins, who said he’s spoken with more than eight leaders with conservative constituencies, including lawmakers. He declined to name them but added: “I do think you’ll see growing momentum toward Rick Santorum.”

Indeed, interviews with a number of leaders, many of whom spoke on the condition of anonymity to be candid, indicated that Santorum was emerging as the preferred alternative to Romney, though a few still are watching Gingrich. Not one mentioned Perry, who announced he would reassess his campaign in light of a fifth-place showing in Iowa only to say a day later he would press on in South Carolina.

Michele Bachmann, the Minnesota congresswoman who is a favorite of evangelicals and the tea party, took the opposite route, abandoning her bid after coming in last in Iowa. That’s left her backers up for grabs and looking for someone to rally behind.

It’s unlikely to be Romney.

Many conservatives have long viewed him skeptically. These voters complain that he’s reversed himself on a series of social issues. They also don’t like his record of support for government health care and exceptions to abortion restrictions. And, with conservatives making up the base of the party, the skepticism has kept his support under 25 percent in most national surveys and in some early primary states despite his front-runner status, strong organization and big bank account.

“You’ll eventually come down to one conservative and Governor Romney,” Gingrich, the former speaker of the House, predicted Thursday in New Hampshire. “And he’ll continue to get 25 percent. By definition at some point in that game somebody is going to start getting a lot more votes than Governor Romney.”

The hand-wringing on the right over Romney as the nominee has produced a deeply unsettled nomination fight.

Conservative voters have spent much of the year flitting from Bachmann to Perry to Gingrich in search of someone to back.

In Iowa, they finally ended up rallying behind Santorum, making him the latest candidate to emerge as the more conservative alternative to Romney.