Four candidates are seriously competing for Florida's votes, and recent polls show more than one have legitimate chances of winning the state's delegates. Unlike any previous contest, no one is sitting Florida out, and for some, their entire campaigns may be on the line. Imagine what happens to the race, then, if the following candidates pulled out a win:

Rudy Giuliani: No candidate needs Florida more. Giuliani has pulled out of every contest he's fought the moment it looked as if he were going to lose -- never has a 50-state strategy been more inaccurately named -- and he's finally decided to make his stand. A win here would give campaign advisers a powerful argument: We told you we were going to win Florida.

Suddenly, donors would open their wallets; the media, which has long ignored the absent Giuliani, would pay attention; poll numbers around the country would almost certainly improve. And Giuliani's national strategy, to be the most famous guy on the ballot, could be back on track. For every candidate, there seems to be a point at which their candidacies are either made or broken. Usually, those points are only known after they happen. For Giuliani, it's been clear for weeks that it's all about Florida.

Mitt Romney: A Romney win would be stunning. For much of the last year, he languished near the double-digit mark before beginning a slow, steady climb that has landed him near the top of the pack. It is ironic, perhaps, that he finds himself in that position after the year he's had: Romney was supposed to win Iowa and New Hampshire to catapult himself toward the nomination. He did neither, and yet many still believe he is the only viable candidate left to beat John McCain.

A Romney win would likely knock Giuliani from the race and set the Bay Stater up for a clear showdown with McCain. Romney can afford national airtime leading up to February 5, but McCain's lead nationally, and in key Super Tuesday states, would ensure his worst-case scenario would be a split. The upshot of a Romney win in Florida: A very long Republican campaign that extends into March.

John McCain: Perhaps the most likely scenario at the moment, a McCain win would cement the one-time also-ran as the heavy favorite to win the GOP nomination. Romney and Giuliani need a platform from which to spring into Super Tuesday. McCain already has his, and a Florida win would both boost his chances and deny the others theirs.

McCain came in second in Louisiana, behind "uncommitted," indicating that, in the absence of knowledge about other candidates, Republican primary voters will back him, not Giuliani. He is, in essence, the default candidate. The only way another candidate takes that mantle away from him is to notch a victory and dominate the news coverage for several days after, then to follow it up with another win. If McCain takes Florida, those opportunities for other candidates basically disappear.

Mike Huckabee: Let's be honest, Huckabee is not going to win Florida. With no money to advertise and a messenger who has sounded downright gloomy lately, the campaign just can't compete with three better-known challengers. So, why not hit the February 5 trail now instead of doing so after a disappointing finish on January 29?

Huckabee is still in second place in most national polls. He has a following. He could draw big crowds in states with heavy evangelical populations that vote on Super Tuesday, including Alabama, Arkansas, Georgia, Missouri and Oklahoma. Even California has a large number of evangelicals Huckabee might poach, and perhaps they would help replenish his barren campaign coffers. Bottom line: Huckabee won't win Florida, so why waste the time and energy trying?

At the moment, McCain holds a fraction of a point lead over Romney in the latest RCP Florida Average. Giuliani is just over 3 points back, while Huckabee trails five points behind him. Tonight's debate, in Boca Raton, is crucial to all four. Whoever comes out on top tonight might just propel themselves to making one of these hypotheticals become reality.