Former Vermont Gov. Howard Dean is dropping his bid to be the next chairman of the Democratic National Committee. Dean, a former DNC chair, made the announcement on Friday in a pre-recorded video at a conference in Denver. Dean served as party chair from 2005 to 2009. Minnesota Rep. Keith Ellison is seen as the frontrunner for the position, which will be vacated when interim chair Donna Brazile leaves. Ellison has the backing of top Democrats, including Sen. Bernie Sanders.