It's the day when the most states vote and the most delegates are at stake. It can be determinative in who becomes the presidential nominee for either party.
More Republicans have voted in early primary states than ever before, while Democratic turnout has dropped off from 2008's historic numbers. But that might not equal success in November for the GOP.
In any normal year, a Republican who wins big in New Hampshire and South Carolina would practically be seen as the presumptive nominee. So why isn't that happening this year?
Evangelical voters have faith in Donald Trump, but there's still an opening for Marco Rubio in a much clearer establishment lane after Jeb Bush's exit. Plus: Clinton wins big with older, black voters.
The former Florida governor, a son and brother of presidents, raised enormous amounts of money and spent more on TV ads than any other candidate, but he couldn't overcome a change-hungry electorate.
A superPAC supporting Ted Cruz is hitting Donald Trump in South Carolina for wanting the Confederate battle flag removed from the state capitol, something the state's Republican governor supported.
A new analysis shows that outside groups supporting Ted Cruz have run nearly double the ads of pro-Jeb Bush behemoth Right To Rise USA. Here's how the other candidates stack up leading into Saturday.
South Carolina is living up to its reputation for nasty politics. Cruz is being accused of being a "liar" who is playing dirty tricks. He hopes religious conservatives will side with him.
Democrats in Nevada go to the polls in what's shaping up to be another tight contest between Bernie Sanders and Hillary Clinton. In South Carolina, will Donald Trump pull off another double-digit win?