Fred Thompson has filmed a closing argument for South Carolina Republicans. In the ad, Thompson stresses his opposition to "amnesty" and his long-held conservative record. Recent polling has Thompson in fourth place in South Carolina. An unexpected outcome in Michigan - say, Romney winning and Huck fading - may provide Thompson an opening in South Carolina. Unlikely, I know, but it looks like anything is possible this year. UPDATE, 3:30 p.m.: New Rasmussen numbers have Thompson gaining vis-a-vis Huckabee.