The presidential candidates have two voting contests behind them and are preparing for the third in South Carolina.

CBS News political director John Dickerson says he doesn't expect any "southern cordiality" as the race makes its way below the Mason-Dixon line.

"The South Carolina Republican primary has a history for being bruising, particularly for the winner of the New Hampshire primary," Dickerson explained.

For example, John McCain won in New Hampshire in 2000 but lost to George W. Bush in South Carolina. The same thing happened in 2012, when Mitt Romney lost to Newt Gingrich right after a New Hampshire win.

To hear why Dickerson thinks different candidates succeed in South Carolina, watch the video above.