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.