At this point, the top targets are in Montana (Tester), Virginia (Webb), Nebraska (Ben Nelson), Florida (Bill Nelson) and North Dakota (Conrad). To my way of thinking, Missouri's Claire McCaskill also belongs on that list; she is from a bellwether state that's taken a decisive red tone, and McCain eked out a win there in 2008. She was also one of Obama's first and loudest supporters.
McCaskill has been one of those Democrat politicians who talk moderately at home, and then go to D.C. and vote in lockstep with the farthest left fringe of their party. It's time someone called her on it, and a top-flight crew of GOP challengers in the Show-Me State look ready to do just that.