South Carolina is a social conservative bastion. Whether or not he actually wins the primary, the fact that Romney will not be soundly defeated in South Carolina constitutes a moral victory for him, and indicates that he has the Republican nomination all but sewn up. If he actually wins, the nomination will be a done deal, even if Gingrich and Santorum keep campaigning. Whoever "wins" South Carolina, it is nearly impossible to imagine either Gingrich or Santorum going on to claim the nomination over Romney.
The more interesting feature of the South Carolina primary is to see how many votes non-candidate Herman Cain garners on behalf of Stephen Colbert. Colbert, who announced his candidacy last week, could not get on the ballot, but Cain's name remains on the ballot, despite the fact that he dropped out of the contest weeks ago. Yesterday, ex-candidate Cain and Colbert appeared together at a rally at the College of Charleston.
Colbert's faux campaign is designed, in non-coordination with the "Definitely Not Coordinating with Stephen Colbert Super PAC," to illustrate the detrimental consequences of the Supreme Court's 2010 ruling in Citizens United, which declared corporations to be people for purposes of first amendment rights, including the right to fund political advertisements. As a practical matter, I don't know that the Court's ruling has changed campaign finance as much as its critics have argued. I do, however, greatly appreciate the way Colbert and Jon Stewart are shining a very bright light on the general problem of financing political campaigns.