Who will it be? Tonight marks the third big Republican presidential primary, and Texas Gov. Rick Perry's exit from the race this week leaves more room for remaining candidates Newt Gingrich, Rick Santorum, Ron Paul and Mitt Romney.

And according to the Washington Post, "South Carolina has picked every Republican nominee since its front-of-the-calendar primary began in 1980." So while the candidates have been splitting votes in Iowa and New Hampshire, tonight's results could very well dictate who will challenge President Barack Obama.

You can see live election results below to find out who's leading as the votes come in.