Ron Paul’s rallies this year have yielded quirky and eclectic crowds — bow-tie-wearing libertarians, scruffy anti-establishment types, large religious families and packs of antiwar college students, all drawn with an unusual fervor to the presidential candidate’s unique libertarian message.

Many mainstream Republicans have long viewed his supporters as a fringe element. But they face a gnawing question: What if Paul’s followers do not fall in line behind the eventual GOP nominee, who will need every vote possible to defeat President Obama in the fall?

A significant share of Paul voters — 35 percent of those in a Michigan exit poll last week — say they would not vote for any other GOP candidate. And even as Paul’s rivals adopt some of his rhetoric, it remains to be seen whether his followers will shift their allegiance.

“I just don’t see it,” said Omer Rafi, 24, a college student and owner of a polo equipment company in Woodbridge. “The establishment, they marginalize not just Ron Paul but the supporters as well. They call us cultists and all sorts of names: ‘Paul-bots.’ ‘Obsessive.’ After treating us like that, I don’t know how they can feel like we are supposed to become obligated to these guys.”

Rafi was among 2,000 supporters who gathered for a Paul rally last week in Springfield, a characteristically large crowd for the candidate, who has gained renown by calling for the elimination of the Federal Reserve, a drastic reduction in the size and scope of government, a return to the gold standard, and an end to most U.S. intervention overseas.

“It’s great to see the young people leading the charge, but we also see others at different age groups,” Paul told the crowd. “Ones who have been frustrated. The ones who have been independents. The ones who have dropped out. And even the frustrated Democrats have come over and said, ‘This understanding of liberty is good.’ . . . When this revolution is successful, it will not be a Republican monopoly at all.”

Paul has yet to win a nominating contest, and as of Monday he had the least number of delegates among the GOP contenders. And he is not expected to fare better in Virginia, even though he and Mitt Romney are the only two candidates on the Republican ballot there. Despite plans by some Rick Santorum and Newt Gingrich supporters to vote for Paul as a protest against Romney, the former Massachusetts governor remains the heavy favorite in Virginia.

Paul has given no indication that he plans to run in the fall as an independent, but such a move would be devastating to the eventual nominee. A December Washington Post-ABC News poll showed that as a third-party candidate, Paul would drain crucial votes from the Republican nominee and virtually guarantee an Obama victory.

Paul’s close relationship with Romney has spawned speculation that he may ultimately endorse the former governor, a possibility that draws laughter from some of Paul’s most hard-core followers.

“I just can’t see him doing anything like that. Those two are about as far apart as you can think of,” said Jeff Benninger, 52, a freight courier from Annandale who said he is more likely to vote for a third-party candidate in the fall.

Paul’s campaign staff has tried to erode the perception that his support consists of a cult of personality around the 76-year-old congressman, who has run for president twice before.

“Four years ago, it felt like people were about Ron Paul and nobody else. It was not cultish, but it was less issue-driven and more about the man,” said a Paul campaign official, who spoke on the condition of anonymity to talk freely about internal discussions. “Now it’s more issue-driven.”

Officials with the other campaigns say some of Paul’s supporters can be wooed. Even Obama’s campaign plans to court disaffected Paul backers, highlighting their common ground on the budget and foreign policy.

Rick Tyler, who heads a super PAC supporting Gingrich, said the involvement of Paul activists would be a boon to the GOP in a general election.

“Their energy is amazing,” he said, particularly among young people, one of the GOP’s weakest groups. But, he added, “many of them, they cannot concede a point ever. Ron Paul is right about everything, and if you bring up a countervailing point, they get mad at you rather than admit that’s a good point.”

Many of Paul’s supporters say they dread the general election, aware that Paul is unlikely to be on the ticket and deeply uncomfortable with the idea of casting a ballot for Romney. They will wait to hear from the man himself, knowing that Paul, ever the meticulous thinker, will have carefully considered the question of whether to endorse.

“I’m sure the Paul campaign will have some marching orders,” said Demetrios “James” Kifonidis, 35, a small-business owner from Fairfax who voted for Obama four years ago. “We trust the guy.”