Mitt Romney's big victory in New Hampshire was decisive, but expected, which means it will take another 10 days — and another vote in South Carolina — before any more Republican contenders are driven from the race. While many of the candidates were looking for a boost from the first primary vote last night, most had already pinned their hopes to the Palmetto State on the belief that the first Southern primary would be a truer measure of how Republicans feel about this election.

While not always deciding an overall winner, Iowa and New Hampshire would normally weed out some of the weaker candidates, but it appears that the remaining group plans to hold on until at least January 21. The most obvious target for elimination right now is Rick Perry, who nearly dropped out after a disappointing finish in the Iowa caucus, then stayed in, only to garner a pathetic 1% of the vote in New Hampshire. But Perry had already staked his plans on South Carolina, a Southern state that he hopes will be more friendly to his style of politics. After giving up on New Hampshire, he has to at least see that strategy out. 

Next would be Jon Huntsman, whose third place finish would be respectable in most circumstances, but will hardly be enough to justify a further push through unfriendly Southern primaries (where he's polling in single digits.) He's unlikely to quit while at the apex of his run, but he has to be disappointed that he could not gain more traction in a friendly state like New Hampshire. He probably has enough "momentum" to stick it out another week, but the writing is obviously on the wall.

The virtual tie between Rick Santorum and Newt Gingrich underscored the trouble that each has had distinguishing themselves as the best anti-Romney social conservative choice. They have also been focusing their energy on South Carolina, however, and will need to make a big move there to justify the continuation of their own campaigns. Santorum may have lost the most ground following a big Iowa showing, but can still get his groove back with another surge in the coming days. Gingrich, meanwhile, seems content to bury Romney in unflattering ads and will not be going anywhere for awhile.

The biggest question mark may be Ron Paul, who is still being treated like a fringe candidate despite two strong showings in the first two states. However, beating expectations is the key to any primary fight and it's possible that his New Hampshire finish will continue to boost him past his rivals. If he can ride his current momentum to another second place finish, he might become a much more attractive option for Republican voters.

For Mitt Romney, the slow and steady race continues. He now has two victories in two states and while a third in South Carolina may not be "decisive" from the standpoint of convention delegates, he remains the candidate that's best equipped for the long haul. South Carolina will certainly be his toughest fight yet, but the cushion of the first two states means he doesn't have to bank on a total victory there to prove he's viable. If he does get a third win, however, the inevitability of his nomination will start to sink in. Other candidates may be able to push on long past their sell-by date, but the fact remains that they are still measured not by their ability to win it all, but by their ability to challenge him. The next vote will be a crucial test of that standard.