If no Republican candidate drops out after Florida, what happens? I'm glad you asked, because the answer is excruciating.
On February 4, Republicans will caucus and choose 28 delegates in Nevada. Four years ago, Romney had the caucuses pretty much to himself and to Ron Paul. This year, he'll have to face a much stronger Paul, a Santorum who's grasping for delegates wherever he can, and a Gingrich who has Sheldon Adelson stuffing $10,000 bills in his pocket.
After that... not much, actually. In the early weeks of February, Republicans in Maine, Minnesota, and Colorado will meet at precinct caucuses. The results are not binding -- like Iowa, they'll be stories of so-and-so's momentum, what's-his-name's total collapse. No more delegates are actually chosen until February 25, when Republicans in the Northern Marianas Islands convene and choose 6 of 9 delegates. Yes, that's right. The Northern Marianas Islands has three-fifths as many delegates as New Hampshire.
We leave the Pacific and come -- finally! -- to the February 28 primaries in Arizona and Michigan. Total number of delegates at stake: A pathetic 59. Arizona's 29 delegates will go to whoever gets the most votes there, no proportional representation. That rule screwed things up for Romney in 2008, when he lost to John McCain by only 12 points, but won zero delegates. Michigan divvies up its delegates proportionately, and by district. If Newt wins by one point in Arizona, he nets 29 delegates; if Mitt wins by one in Michigan, he might net four or five. After two months of primaries, Republicans will have assigned 7.9 percent of their delegates, with no candidate having more than 150 or so of the 1,144 they need.
When do we actually start assigning delegates? March 6, Super Tuesday, when Alaska, Georgia, Idaho, Massachusetts, North Dakota, Ohio, Oklahoma, Tennessee, Vermont, and Virginia vote, and assign 374 of the suckers. That's how long this can last, at the very least.
Side note: You know what would have been useful for Romney? An early Utah primary, a winner-take-all state that he crushed in 2008. That year, Utah voted in February. This year? It's the very last primary, June 26. Call it "Huntsman's revenge."