South Carolinians are voting today in the GOP primary, which some pundits see as the candidates' last stand for getting the GOP nomination to run in the general election. On weekends on All Things Considered today, host Guy Raz talked with Danielle Vinson, the chair of the political science department at Furman University in Greenville, S.C., about what is often considered "dirty" South Carolina primary politics. "If you don't come of out here with a first or second place, it's hard to keep going," she says. "So by the time they get here everybody takes off the gloves." One of...