The Democratic primary race entered a new phase on Friday night, with Vermont Sen. Bernie Sanders and former Gov. Martin O'Malley escalating their attacks on front-runner Hillary Rodham Clinton. With her numbers on the rise after a summer slump, Clinton finds herself increasingly targeted by her primary opponents — a marked tonal shift for a race that stayed largely civil for much of the early primary. But in South Carolina on Friday night, there was far less Southern gentility on display. In individual interviews with MSNBC host Rachel Maddow, both Sen. Bernie Sanders and former Gov. Martin O'Malley cast themselves as the party's liberal standard-bearers, questioning Clinton's commitment to the causes Democrats hold dear.