MANCHESTER, N.H. -- Mitt Romney is poised for a big win at the New Hampshire 2012 primary, but if he takes the Republican nomination from Ron Paul, Paul's supporters may make him regret taking on the Texas libertarian.

On the ground at the New Hampshire primary, numerous voters and supporters voting for Rep. Paul today said that if Mitt Romney won the nomination, they would write Ron Paul's name in on the presidential ballot instead, cutting crucial votes away from Romney in the general election.

I'll always vote Republican

Across the board, most registered Republicans and independents decided on Mitt Romney, Ron Paul or Jon Huntsman as their candidate of choice. And for Romney and Huntsman supporters, falling in line behind the eventual GOP nominee was a no-brainer.

I'll always vote Republican, one voter, Muriel, said. No matter what they are, I'll vote Republican.

Jennifer, a Jon Huntsman supporter who describes her choice as a breath of fresh air, is also ready to follow her party's lead, even if the nominee is someone she's less than enthusiastic about, like onetime frontrunner Newt Gingrich.

Gingrich I'm not a fan of, she said, but I still think he might be better than Obama.

Most supporters, however, are pretty certain who the establishment choice will be: former Massachusetts Gov. Mitt Romney. And they're prepared to toe that party line come the fall, even if they believe their candidate is the best for the job and the most likely to beat the incumbent president.

Absolutely we'd vote for Romney, said Chase, a Huntsman supporter holding a Jon 2012 sign.

Ron Paul 2012 Not Backing Down

But one group of supporters is not so eager to follow Mitt Romney if their candidate fails to nab the primary. In fact, one of the reasons many are voting for him is to avoid electing either Democrat incumbent Barack Obama or GOP establishment figures like Mitt Romney.

That group is Ron Paul 2012.

Ron Paul's supporters are the only group at the New Hampshire primary who appear to be dedicated to supporting their candidate no matter what the nomination process yields... or, indeed, what effect it may have on the final outcome of the 2012 presidential election.

[I've been a Ron Paul supporter] from the beginning, said Joe, holding a large Paul 2012 sign outside a New Hampshire voting center. I was involved in 2008 as well.

Joe has always been drawn to Paul's pro-liberty message, and has become steadily more concerned about what he views as a continued loss of civil liberties and constitutional rights in America. Like others interviewed outside voting stations across the state, he has never wavered from his support for Paul, or his frustration at being sidelined or denigrated for picking a so-called fringe candidate to back.

I'm afraid that just standing around on the corner holding a Ron Paul sign at some point in the future, for whoever the next Ron Paul is, could be a treasonable offense, he said. And I don't like that.

Joe began campaigning for Ron Paul in October when he and fellow supporters raised around $5,000 in funds, hanging banners all over the state's overpasses and crashing the Gingrich and Romney headquarters in Exeter.

Like many Ron Paul supporters, Joe is hoping for a strong second place in the New Hampshire primary. But if Paul loses the Republican nomination, he plans to write in Paul's name on the general election ballot in November.

The Danger of Write-In Ballots

The problem with massive write-ins, of course, is that it almost always ends up splitting the vote within a party without actually benefitting the actual candidate.

Those who voted for Ralph Nader in 2000 saw George W. Bush elected as president after Democrat Al Gore's support was splintered through his third party movement.

Although Paul has yet to say whether he would run as third party member, the candidate garnered over 40,000 votes in the 2008 election without actively campaigning against Obama. And his supporters are far more determined this year than they were four years ago.

I think I found the only honest politician maybe in my lifetime, said a Paul supporter named Pedro. He has some issues with Paul's statements, but can't get over the candidate's consistency and his integrity.

And although write-ins may end up splintering the Republican party, some voters feel the moral stance taken by voting for Paul is more important thn sticking to the party line.

Pedro and another supporter, Pat, were holding several Ron Paul signs outside a Manchester voting station. Pat, a war veteran, said Paul seemed to be the only one who understood the horror of moderday warfare.

Last year I had a friend of mine who was killed in Afghanistan, and it really made me rethink my stance on foreign wars, Pat said.

I was already on board with the domestic politics, cutting taxes, maximizing freedoms, but I didn't think about it the other way. I didn't think about what other people in other parts of the world think about U.S. troops, right or wrong, going over there.

Pat criticized both Barack Obama and former president George W. Bush for continuing massive wars overseas without having legitimate military experience.

Pedro, like many others at the voting stations, plans to write in Ron Paul's name if he doesn't win the nomination. Pat isn't so sure, but knows that if he doesn't cast his vote for Paul, he won't participate in the 2012 election at all.

I'm back to undeclared

If Ron Paul supporters do launch a mass write-in for the 2012 presidential election, it could spell serious trouble for Mitt Romney. But there's a big difference between vowing to write in a candidate's name in January and actually doing so in the fall.

Christine, for example, a registered independent, finds frontrunner Romney kind of smarmy and has settled on Paul as her candidate. But she's not convinced that her vote will still be for the Texas libertarian come November 2012.

I gotta be honest, I'm not altogether happy with any Republican candidates right now, she said. I'm back to undeclared. I'm a registered independent. I would consider it [voting for someone else] but I'm not 100 percent sure right now.

Could Write-In Throw Election?

Whether or not Ron Paul will be the Ralph Nader of 2012 will not depend on the nomination alone. It will also be about whether his supporters can wait at least another four years for yet another chance to get Paul into the White House.

Though many Ron Paul supporters interviewed were independents, none of them had been planning to vote for Obama in 2012, and would vote Republican if Paul is chosen as the GOP nominee. Casting their votes for another Republican can only help Obama in his re-election bid.

If Paul is offered the vice presidency or a possible Cabinet post, it's likely his supporters will decide to toe the party line.

But if Ron Paul is dismissed by the GOP establishment, just as he was dismissed for much of the early campaign, Mitt Romney may find his chances of winning the 2012 presidential election significantly cut down.