Facing a tough race in 2014, three-term Sen. Tim Johnson (D) of South Dakota announced his decision to retire at the end of 2014, giving Republicans another shot at one of six seats they need to take back control of the Senate.
"You have supported me in multiple elections, and, more importantly, your patience and prayers enabled me to recover from a life-threatening brain injury," said Senator Johnson, in a statement. "I will be 68 years old at the end of this term and it is time for me to say good-bye," he added, pledging to use the balance of his term to "find a bipartisan solution" to the nation's challenges.
South Dakota, with its largely conservative electorate, was a top target for Republicans well before Senator Johnson made his decision public on March 26. Former Gov. Mike Rounds, a popular Republican, announced his intention to run for the seat in December and become the instant frontrunner.
State Senate majority whip Larry Rhoden, who is running to the right of Rounds, and physician Annette Bosworth are in the race, and, as of Aug. 18, State Rep. Stace Nelson is expected to join them.
But national conservative groups have pushed hard to find an alternative to Rounds, whose record they see as too moderate. Two-term Rep. Kristie Noem, elected with strong tea party backing, was their dream pick, but she declined to run. The search continues.
State Democrats are also still scrambling for a top-tier candidate. Rep. Stephanie Herseth Sandlin, who was defeated by Ms. Noem in 2010 but remains popular in the state, declined to run. That leaves Rick Weiland, a former congressional staffer who lost a House bid in 1996, as the Democratic candidate left standing.
GOP officials say they are confident of a win in South Dakota, regardless of who emerges as the Democratic candidate.
"South Dakota voters rejected the progressive agenda by nearly 20 points in 2012 and it's a prime pick up opportunity for Republicans regardless of whose name ends up on the ballot," said Sen. Jerry Moran (R) of Kansas, who chairs the National Republican Senatorial Committee, in a statement.