House Majority Whip Jim Clyburn plans to endorse former Vice President Joe Biden. According to Politico, Clyburn is the highest ranking African American in Congress. Pressure to endorse Biden grew after Sen. Bernie Sanders won Nevada by a landslide. Three top campaign sources said Biden told Clyburn how badly he needs the endorsement. A Biden campaign adviser said he was going to wait until after the debate to give the endorsement.