The Republican presidential candidates face their first real voting contest in Tuesday's Iowa caucuses. But, as is the case in all contests, someone has to lose - in this case, a few people have to lose.

Expectations have been set: Mitt Romney and Ron Paul are at the top of the latest polls, and Rick Santorum is picking up steam just in time. Meanwhile, Newt Gingrich, Rick Perry and Michele Bachmann are treading water. Jon Huntsman isn't even there.

Luckily for the losers, there are still three other primaries in January. Here's a rough guide to the candidates' options and best chances if they don't meet expectations in Iowa.

Mitt Romney

Romney wasn't seen as a viable winner in Iowa until recently; he's put most of his effort into winning the New Hampshire primary a week later. And that primary, on Jan. 10, could mean a lot for Romney if he comes up short in Iowa - say, finishing behind Gingrich or Santorum as well as Paul.

"Romney has done exceptionally well in caucuses in the past," said Eitan Hersh, a political science professor at Yale University. "If he comes in second to Paul, basically that will be the equivalent of coming in first."

South Carolina's primary, on Jan. 21, is where Romney risks a lot if he doesn't separate himself from the pack in the first two nominating contests. In 2008, he had trouble winning over the state's evangelical Christians, and after spending money and effort there, he pulled out shortly before the primary because he couldn't win. But that's only a major problem this time around if he doesn't live up to expectations in New Hampshire.

Newt Gingrich

Speaking of South Carolina, that might be a haven for Gingrich if he can't finish in the top tier in Iowa or New Hampshire. He's already said that he'll be attacking Romney "every day" after Iowa, and with enough money Gingrich can argue loudly in a conservative state that Romney is too moderate for the Republican Party.

Then there's Florida's primary, too, at the end of the month. If Gingrich can't reclaim the surge he enjoyed just a few weeks ago by then, it's probably too late for him.

"In some ways, he has to do what Giuliani tried to do in 2008 - to be a national figure that attempts to kind of win general audiences without much local organization and with a lot of opposition from party elites," Hersh said.

Ron Paul

Despite Paul's status in Iowa, most political insiders have written him off as a serious contender for the Republican nomination. But that doesn't mean he can't be a kingmaker in the event that two other candidates prolong the primary process until the summer convention.

In this case, Paul's best friend might be Gingrich. If the former House speaker can split votes with Romney until the convention, and Paul stays in the race with his smaller but reliable votes from loyal supporters, he could direct them one way or another and ultimately choose the nominee.

Ideally, he'd do that in exchange for a nice position in an administration, of course.

"That's the opportunity for him to exert an amazingly large amount of power," Hersh said.

Rick Santorum

Santorum will probably emerge Tuesday night being able to say that he exceeded expectations in Iowa as the beneficiary of a conveniently timed surge in popularity. But short of a top-three finish, Santorum lacks the resources and organization that a multi-state campaign demands.

A wild card could be the demographics in South Carolina, where there's more of a military presence than in other early voting states. If Santorum can parachute into the state talking about American strength around the world, "it might resonate in South Carolina the way it might not in Iowa or New Hampshire," said Mike Franc, the vice president of government studies at the conservative-leaning Heritage Foundation.

By the end of January, Santorum might be in the same position as Bachmann - an established conservative hoping for a spot in a Republican administration (especially if that Republican is Romney and he's trying to prove to the right wing that he's conservative enough).

Michele Bachmann

Bachmann's presidential hopes are dimming, but she still might have a shot at the White House - as a pick for vice president.

While Bachmann rounds out the bottom end of the polls in Iowa, she's still an admired figure in the tea party and could be called upon to shore up support among that key constituency (especially if the nominee were a more moderate guy, like Romney).

"I think that what Michele Bachmann's doing right now is sort of competing for credibility within the party," said Michael Heaney, a political science professor at the University of Michigan. "If not vice president, she could be looking at a prominent cabinet position."

Rick Perry

Perry's Southern appeal could be a huge help in South Carolina and in Florida. He's not likely to finish high in Iowa, and he's ignored New Hampshire, so those last two January primaries are his only real hope of staying relevant in the first month of the contest.

What helps Perry is a reliable donor base (he brought in $17 million in seven weeks once he jumped into the race), and a strong talking point about his job-creation record as the governor of Texas. But if Romney is able to hold the lead after the New Hampshire vote, Perry is in danger of simply losing attention in the media to a Romney-vs.-Obama narrative that could shape up by then.

"Let's say Rick Perry has a demographic advantage there because he's a Southerner," Heaney said. "A lot of that will be erased by the media attention" given to Romney.