Thune, who is 63 and in his fourth Senate term, has promised to work closely with President-elect Donald Trump despite differences between the two over the years.

Senator John Thune (R-S.D.) has been elected as the new leader of Senate Republicans, succeeding Mitch McConnell, who held the position for 18 years, according to sources present at the closed-door vote.

U.S. Senate Republicans on Wednesday elected South Dakota Sen. John Thune as that chamber’s next majority leader during a closed-door, secret ballot election.