BERNIE SANDERS - His big win in New Hampshire has done exactly what you would expect, as it gave Sanders sudden momentum that allowed him to compete in a state like Nevada. Sanders hasn't spent much time in Nevada, but still hopes to pull off an upset on Saturday - which would then give him even more momentum, and allow him to close the gap in South Carolina and the March 1 Super Tuesday states.
SOUTH CAROLINA REPUBLICAN PRIMARY - Polls open 7 am to 7 pm ET
DONALD TRUMP - Only once since last July has Donald Trump not led in the polls in South Carolina, which makes it kind of hard to believe that somehow he is going to collapse coming down the stretch. Trump spent most of the last 10 days on the offensive against Ted Cruz, repeatedly labeling him a liar, as Trump barely mentioned the rest of the GOP field. A win could put him on a roll into Nevada next Tuesday, and then the March 1 primaries and caucuses on Super Tuesday. A loss to either Cruz or Rubio would be a major setback, and might result in big changes in the polls in the March 1 states.
TED CRUZ - This was supposed to be a state where Cruz could stop Trump with better organization and the votes of more religious conservative voters. But Cruz has struggled to deal with Trump's "liar" attacks; the Cruz jab that Trump is not a real conservative doesn't seem to have worked. Still, I wonder if the Cruz GOTV (Get Out The Vote) efforts will mean that he can outperform what the polls say. Or maybe Cruz has been really hurt by the Trump attacks. A win would be huge for Cruz. Second place would be expected. Third place behind Trump and Marco Rubio might be seen as a disaster.
MARCO RUBIO - After getting the late momentum in Iowa, Rubio's rise was derailed by his bad debate performance in New Hampshire; but he seems to have regained some of that positive mojo in recent days. Winning the endorsement of Gov. Nikki Haley seems like it has helped, though the polls are mixed - some have shown hardly any bump, while others depict a huge rush to Rubio in the last two days. Which is it? Even a third place finish that's well ahead of Jeb Bush would help Rubio. Finishing second ahead of Cruz would be a real big jolt. A Rubio win could totally change the nature of this race going to Nevada and Super Tuesday.
JOHN KASICH - Kasich won't even be in South Carolina on Saturday, as he goes to Massachusetts and Vermont to campaign - those are states that vote on March 1. Kasich is skipping Nevada's caucus next week. The Ohio Governor was well received in the Palmetto State, but really is not expected to do that well. Finishing third here would be a major accomplishment. Anything above that would be a game-changer for his candidacy. Double digits would be reason for champagne on the Kasich bus.
JEB BUSH - When the stories in the last few days of the primary campaign are about whether your campaign staffers are looking for new jobs or that they might no longer be paid - that's not the message you want, but it is what confronts Jeb Bush. To stay alive, Bush needs to outpace Marco Rubio, but the polls indicate that might be a difficult assignment. I saw Bush's father win here in South Carolina over Pat Buchanan in 1992 and then watched his brother win over John McCain in 2000. At no point this past week did I sense any such Bush Family Momentum for the former Florida Governor.
BEN CARSON - After basically sitting out New Hampshire, Ben Carson has been much more active in South Carolina, not only in terms of campaign events, but also on the airwaves. In my lengthy travels over the last few days, I heard all kinds of Carson ads on a variety of radio stations. One would think that if Carson had quit the race, some of his supporters might have moved over to Ted Cruz - so if Carson wins 6-8 percent, there will be a lot of votes there that Cruz missed out on in the Palmetto State.