Most expect Rounds to make a bid for Sen. Tim JohnsonTim JohnsonCourt ruling could be game changer for Dems in Nevada Bank lobbyists counting down to Shelby’s exit Former GOP senator endorses Clinton after Orlando shooting MORE's (D-S.D.) seat: He already has an exploratory committee open for the seat and state Sen. Don Lederman (R), a friend of the former governor's, told the Sioux City Journal on Wednesday that Rounds will run. Rounds has three events planned in the state on Thursday.

Johnson has not said whether he'll run for another term in the heavily Republican state. He has $1.2 million in the bank if he does decide to run again.