Sen. John Thune will replace Sen. Mitch McConnell (R-Ky.) as Republican Senate Majority Leader after a close race that required two votes to be decided Wednesday.
Mr. Thune, Mr. McConnell's chief of staff and a favorite of the establishment, must use Mr. McConnell's iron hand to lead a conference demanding change. He will also be tasked with shepherding President Donald Trump's policies through the Senate, moving nominees forward quickly and promoting Trump's aggressive legislative agenda.
Thune received 23 votes in the first round, four votes short of clinching victory. Sen. John Cornyn (R-Texas) received 15 votes and Sen. Rick Scott received 13 votes.
In the second vote, Mr. Thune defeated Mr. Cornyn 29-24.
Republicans convened Tuesday night for a leadership forum hosted by Sen. Mike Lee (R-Utah) to discuss who is best to lead the party through the Trump administration and beyond.
These discussions come after Mr. McConnell has often partnered with Democrats to advance bills that conservatives dislike, especially spending bills, and how to restore more autonomy to individual senators and influence conservative policies. The focus was on how to promote this effectively.
Scott, a conservative favorite, appeared to gain momentum after the forum. His candidacy likely marked the beginning of concessions from Mr. Thune and Mr. Cornyn.
Mr. McConnell served for 18 years. It's unlikely that Tune will match that record reign.
But Thune, who is generally viewed as the favorite despite his past hostility toward Trump, will have to overcome the challenges of a much different Senate made up of Republicans more pro-Trump.

