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.

Thune beat out two other competitors, Sens. John Cornyn and Rick Scott, by gaining majority support from GOP senators in a secret ballot vote.

Cornyn had for years signaled he wanted to succeed his close ally GOP leader Mitch McConnell. On Wednesday, he lost in a vote decided by the Republican members of the Senate.