SC FlagAfter a big win in New Hampshire, Mitt Romney is headed to South Carolina along with the other Republican candidates, for what could be the last big showdown over who will be the Republican nominee.

Most agree that a Romney win in South Carolina will be the death knell for the other candidates' campaigns -- but his competitors aren't going down without a fight. Ron Paul, Rick Santorum, Jon Huntsman, Rick Perry and Newt Gingrich will all be campaigning hard over the next ten days leading up to the January 21st primary, and you can be assured that reporters from around the world will be covering every minute of it.

To get you ready for this battle royale, I've put together a list of everything you need to know about the South Carolina primary, so that you can sound knowledgeable when you're discussing the presidential race with the other playgroup moms. Or your handyman. Or your fellow epidemiologists at the Centers for Disease Control. Whatever. You'll know your stuff. Read on ...

  • South Carolina's timing as the third state in the primary caucus process was designed purely to stop the momentum "undesirable" candidates might gain from wins or near-wins in Iowa and New Hampshire.
  • The winner of South Carolina's Republican primary has ended up winning the nomination in every election since 1980.
  • South Carolina is chock full of social and Tea Party conservatives. Like most southern states, it's got a church on every corner (figuratively speaking) and religion heavily influences politics. Personally, I expect Rick Santorum to do well in this primary. He'll appeal to these voters in the same way that he appealed to social conservatives in Iowa. Newt Gingrich also has strong appeal as a Southern conservative. On the flip side, Romney, with his Mormon roots, may have some trouble.

  • Romney may be aided in South Carolina by a recent influx of Yankees to the state, and by the fact that electability is important to voters in South Carolina -- They treasure their perfect record of choosing the ultimate Republican nominee. Another element in his favor-- polls are suggesting that S.C. voters consider the economy to be far more important than social issues.

  • South Carolina voters don't have to register as Republicans or Democrats, and can vote in either primary.

  • South Carolina has a 9.9% unemployment rate. Jobs are going to be a big topic of discussion for the candidates here.

  • While Mitt Romney was at the helm of Bain Capital, the investment firm shut down a plant in Gaffney, South Carolina and laid off 150 workers. Meanwhile, Bain reportedly made millions from the deal. You can be sure the other candidates are going to play this story up in their campaign speeches. Meanwhile, a super PAC supporting Romney plans to spend $2.4 million on South Carolina ads.

  • Speaking of Bain Capital, a Romney adviser is predicting a "bloody mess" for Romney in South Carolina, with candidates going all out in their attacks against him, including $3.4 million being spent by a pro-Gingrich super PAC on anti-Romney ads and a 27-minute online documentary.

  • Current polls in South Carolina all show Romney with a clear lead, followed by Gingrich and Santorum, who are basically tied right now for second. Ron Paul is a distant fourth.

  • Don't put too much stock in those polls, though. About half of South Carolina's likely GOP voters say they're still undecided about whom they'll ultimately choose.

That should be enough to get you started. In the meantime...

Who do you think will win South Carolina?