We may soon come to the point - less than two weeks, potentially - where the nomination contest will be all but over.
Without any sort of comeback by Rick Perry, or continued momentum by Rick Santorum, or a return to good graces for the campaign of Newt Gingrich, we may be looking at Mitt Romney sealing the deal on a nomination on March 6, when sixteen states hold their primaries on Super Tuesday.
Mathematically, Romney won't get there on March 6. He may make the gap large enough that no other candidate stands a realistic chance of catching him.
The idea of "momentum", though, won't matter on March 6. It will matter on January 21. Despite Iowa and New Hampshire's perceived importance in nomination races, it has been South Carolina that has been the bellwether, the firewall, the holding ground that has spurred on recent campaigns to victory.
Since 1980, no candidate has won the Republican nomination without a victory in South Carolina. New Hampshire and Iowa do not sport such a track record - New Hampshire was won by someone other than the nominee in 1996 and 2000, while Iowa has managed to miss the eventual nominee in 1980, 1988, and 2008.
South Carolina has gone 8-for-8.
If Romney takes South Carolina, the "momentum" charge will come to fruition. Other candidates won't draw in enough to contend, and may drop out sooner than hoped. It will be wrapped up quickly. On the bright side, it might free you up for working on a Senate campaign - since there are plenty of big races in that chamber.
Bottom line: if you want your candidate (not named Romney) to have a fighting chance in this race, you're going to have to do something in South Carolina over the next twelve days.
Hopefully, I'll be at the SRLC starting January 18th. Will you?