Tea party activists are struggling to rally behind a single presidential contender as disparate groups with conflicting priorities balance candidate viability with conservative purity on policies that extend well beyond the spending concerns that spawned the movement just two years ago.

And Republican presidential campaigns are actively courting the grass-roots conservative movement for the passion, money and army of volunteers that fueled massive Republican gains last fall.

“Whoever the Republican nominee is, if they want to defeat [President Barack] Obama, they need to have the support of the tea party movement,” Tim Pawlenty spokesman Alex Conant told Roll Call.

Reading between the lines, of course, one sees the suggestion that a GOP presidential candidate would not survive tea party hostility. And looking back at the last election cycle, it’s apparent the tea party is perhaps better suited to tear down candidates than to propel them to victory.

That was certainly the case with 2010 Senate races in Delaware, Alaska and Colorado.

“They weren’t all that successful at getting folks nominated or elected, but they were really good at taking out moderate or establishment types,” said a top staffer on a Republican presidential campaign. “It may be the same thing in 2012.”

Mitt Romney hopes not.

As the field begins to solidify, the former Massachusetts governor has drawn the ire of national tea party groups more than any other presidential contender.

Outspoken tea party ally FreedomWorks, under the direction of former House Majority Leader Dick Armey (R-Texas), is among the most active Romney agitators. Romney opponents on the right cite the universal health care law bearing his signatpure in Massachusetts, the measure that inspired Obama’s health care overhaul that activists loathe.

Matt Kibbe, president of FreedomWorks, told Roll Call that his group has been hard-pressed to find Romney supporters on the ground. “All of the candidates, except for Romney, are talking our language,” Kibbe said, adding that tea partyers have been frustrated with former Speaker Newt Gingrich (R-Ga.).

The Tea Party Patriots also haven’t shied away from bashing Romney, the frontrunner in national polls who battled similar claims that he was not conservative enough during his 2008 bid.

“As national coordinators of the largest tea party group in the country, we’ve heard little support for Romney in the movement as we interact daily with local coordinators and activists,” said Mark Meckler, co-founder and national coordinator of the Tea Party Patriots. “We believe it’s premature to say whether anyone would support him if he were the nominee, and anyone who says that tea partyers would support him is certainly not speaking for the movement at large.”

Meckler’s statement was intended to rebut the recent suggestion of a Tea Party Express leader that the movement would support any Republican over Obama. The testy exchange between supposed allies exposes a fundamental truth about the tea party movement: There are various groups at the local, state and national levels that have little organization and often have clashing priorities, even in the same region.

“Contrary to what the perception might be about tea party activists, I sense this great patience in trying to work to discern who the best candidate is to promote,” said Ovide Lamontagne, who nearly rode the tea party wave to a Senate primary victory in New Hampshire last fall and emerged as a leading conservative voice in the first-in-the-nation primary state. “And that is the person who is the most conservative who can win. Winning is part of the equation — much stronger than it has been in the past.”

Earlier this year Lamontagne openly questioned whether Rep. Michele Bachmann (R-Minn.), whose résumé reads like a tea party dream candidate, could be victorious in a general election. His emphasis on viability suggests that Romney, consistently at the head of national polls among likely Republican voters, could win over tea party activists in the Northeast, despite the health care concern.

But that may not be the case in Iowa.

The Hawkeye State’s grass-roots conservatives are more likely to support former Godfather’s Pizza CEO Herman Cain or Bachmann, according to Michael Fiala, a member of the North Iowa Tea Party and a conservative marketing consultant. Fiala said activists are not worried about the conventional wisdom or polling that suggests those candidates would have a difficult path to the GOP nomination or a general election victory.

“The tea people I know who have stayed active in politics for more than a decade, they remember Ronald Reagan being blown off as a second-tier movie actor, and they remember Jimmy Carter being blown off as a peanut farmer,” Fiala said. “From that perspective, Herman Cain has just as good a shot as anyone else, but he can’t make any mistakes.”

He said social or fiscal issues would trump viability issues, depending on which part of the state the activists hail from. But there seems to be unanimous concern with Romney’s health care policies, Fiala said.

It’s not clear how much influence Iowa’s tea partyers will hold in the February caucuses because the movement did not exist when Hawkeye State Republicans chose former Arkansas Gov. Mike Huckabee as their favorite in 2008. (Romney came in second.)

The differing priorities in the key early states means that courting the tea party movement is no simple task. But the candidates are trying.

“We meet with tea party activists when we travel around the country. And we’ll certainly continue to court them,” Conant said of Pawlenty, who was one of just a handful of hopefuls who appeared at a Tea Party Patriots convention in February.

Indeed, Pawlenty is among at least six presidential hopefuls to participate in an Iowa Tea Party bus tour beginning this week. (For more information, see the sidebar.) Romney, who has done little campaigning in Iowa so far and who will skip the crucial Ames straw poll this summer, is noticeably absent from the bus tour’s roster.

The Romney campaign declined to comment on tea party criticism but cited a March Pew Research Center poll showing that he enjoys broad support from rank-and-file tea party members, if not their outspoken leaders.

Specifically, Romney was the choice of one in four respondents who are tea party supporters. That put him atop the potential GOP field at that time, which included Huckabee, who has since dropped out of the race, libertarian-leaning Rep. Ron Paul (Texas) and former Alaska Gov. Sarah Palin.

Rep. Allen West, who dismisses tea party calls for him to run for president, suggested that it would be months before the movement coalesces around a favorite.

“By September or October, maybe we’ll have a sense,” the Florida Republican said, noting that the field is still being shaped.

While the tea party may seem disjointed and less enthusiastic than it was last fall, West said it would play a major role in the presidential contest.

“They’re still very much engaged,” he said. “It’s kind of like ‘The Blob.’ Remember that old Steve McQueen movie? It kind of pops up, then it goes away. Then it comes back again.”

Either way, West said, the candidates “are going to have to present themselves. They can’t run away from the movement.”

Janie Lorber contributed to this report.