A former campaign volunteer for U.S. Sen. Rand Paul will face charges that he assaulted a liberal activist during last year's general election.On Tuesday, Fayette County District Judge Kim Wilkie refused to throw out the charges against Tim Profitt that he assaulted MoveOn.org activist Lauren Valle. The judge said he based the decision on a video of the incident outside the Kentucky Educational Television studios before a scheduled debate between Paul and Attorney General Jack Conway last October.It shows Profitt and another person wrestling Valle to ground and then it appears that Profitt steps on her neck and shoulders.During the court proceedings, Profitt's attorney filed a motion to dismiss, arguing that his client was justified in using force in order to protect Paul.The judge, however, found that there was probable cause and set the trial for June 20.Profitt is charged with fourth-degree assault, a misdemeanor. If convicted, he faces a maximum sentence of a year in jail and a $500 fine.