Murray, KY – Republican U-S Senate Candidate Trey Grayson has released a commercial attacking opponent Rand Paul as anti-coal. Grayson is airing the ad on television in near Kentucky coalfields. The Grayson ad shows Republican Senate hopeful Rand Paul telling a group in Tennessee that coal is "a very dirty form of energy" and "probably one of the least favorable forms of energy." The ad is running in a heavily Republican mining region. Paul campaign manager David Adams says Paul supports using coal until a better energy source is available. The GOP primary is May 18.