Democratic presidential candidate, former Maryland Gov. Martin O'Malley , left, Democratic presidential candidate, Hillary Clinton and Democratic presidential candidate, Sen. Bernie Sanders, I-Vt, stand together before the start of the NBC, YouTube Democratic presidential debate at the Gaillard Center, Sunday, Jan. 17, 2016, in Charleston, S.C.
Democratic presidential candidate, former Maryland Gov. Martin O'Malley , left, Democratic presidential candidate, Hillary Clinton and Democratic presidential candidate, Sen. Bernie Sanders, I-Vt, stand together before the start of the NBC, YouTube Democratic presidential debate at the Gaillard Center, Sunday, Jan. 17, 2016, in Charleston, S.C. Mic Smith AP
Democratic presidential candidate, former Maryland Gov. Martin O'Malley , left, Democratic presidential candidate, Hillary Clinton and Democratic presidential candidate, Sen. Bernie Sanders, I-Vt, stand together before the start of the NBC, YouTube Democratic presidential debate at the Gaillard Center, Sunday, Jan. 17, 2016, in Charleston, S.C. Mic Smith AP

The Latest: Sharp exchanges in fourth Democratic primary debate and more updates

January 17, 2016 06:57 PM