FILE - In this Aug. 14, 2015, file photo, Democratic presidential candidate Sen. Bernie Sanders, I-Vt., speaks at the at the Iowa Democratic Wing Ding at the Surf Ballroom in Clear Lake, Iowa. The Vermont senator sought to broaden his appeal with black voters Friday, Aug. 21, 2015, in speeches in South Carolina denouncing "institutional racism" in the American political and economic system.
FILE - In this Aug. 14, 2015, file photo, Democratic presidential candidate Sen. Bernie Sanders, I-Vt., speaks at the at the Iowa Democratic Wing Ding at the Surf Ballroom in Clear Lake, Iowa. The Vermont senator sought to broaden his appeal with black voters Friday, Aug. 21, 2015, in speeches in South Carolina denouncing "institutional racism" in the American political and economic system. Charlie Riedel AP
FILE - In this Aug. 14, 2015, file photo, Democratic presidential candidate Sen. Bernie Sanders, I-Vt., speaks at the at the Iowa Democratic Wing Ding at the Surf Ballroom in Clear Lake, Iowa. The Vermont senator sought to broaden his appeal with black voters Friday, Aug. 21, 2015, in speeches in South Carolina denouncing "institutional racism" in the American political and economic system. Charlie Riedel AP