Ex-Gov. Rounds to challenge Sen. Tim Johnson

Former South Dakota Gov. Mike Rounds (R) will run for the Senate, he announced Thursday morning.

Rounds will run for the seat held by Sen. Tim Johnson (D-S.D.), who has yet to say whether he'll run for another term. Rounds, a former two-term governor who won both of his races by double-digit margins and left office in 2011, instantly makes the race competitive in the heavily Republican state.

His decision gives Republicans two early top recruits against red-state Democrats: Rep. Shelley Moore Capito (R-W.Va.) has already announced a bid for the seat of Sen. Jay Rockefeller (D-W.Va.), who hasn't said whether he'll run again.

Johnson has had some health issues, though the most serious were a few years back, when he suffered a stroke. He had $1.2 million in his campaign account at of the end of September.