Chris Cillizza of the Washington Post blog, The Fix, ranks what he thinks will be the most competitive Senate races in 2008. South Dakota ended up tied with Virginia at number eight:
8. South Dakota (tie): Things are starting to get back to normal in the South Dakota political world -- six months after Sen. Tim Johnson (D) nearly died from a brain hemorrhage. It remains an open question whether Johnson will seek reelection; a final decision won't be made until the fall. If he runs, it will be tough to find a serious Republican to challenge him. In an open seat, Republicans would have an immediate advantage due to the GOP lean of the state. Gov. Mike Rounds (R) would likely run in an open seat. Democrats are doing everything they can to create the perception that Johnson is ready to run for a third term. What we don't know is whether or not Dems are engaged in wishful thinking.