Following a closed-door vote, Thune won the leadership role after a tight three-way race between himself and Sens. John Cornyn (R-TX) and Rick Scott (R-FL). It’s a shake-up for Senate Republicans as McConnell held the post for more than 18 years, leaving elected officials and others in and around Washington wondering how Thune will control the upper chamber. 

“I am extremely honored to have earned the support of my colleagues to lead the Senate in the 119th Congress, and I am beyond proud of the work we have done to secure our majority and the White House,” Thune said after being elected. “This Republican team is united behind President Trump’s agenda, and our work starts today.”

Thune has a long history in elected office before becoming the Senate’s leader-elect. He served as South Dakota’s at-large representative in the House from 1997-2003. He did not seek reelection to the House in 2002 in order to run for Senate against incumbent Democratic Sen. Tim Johnson. He lost that race by just 524 votes. 

In 2004, Thune ran against Sen. Tom Daschle (D-SD), the Senate minority leader at the time. He won that election by 4,508 votes, garnering 51% of the vote.

Since then, Thune has consistently been reelected to the Senate, now serving his fourth term. In the Senate, he led the Senate Committee on Commerce, a panel with an expansive portfolio including transportation, telecommunications, science, and consumer protection matters. While in the Senate, Thune has consistently ranked as one of the most conservative lawmakers in Congress, having a lifetime 83.25 out of 100 conservative rating from CPAC.

His current term runs through 2028, which will be the entirety of President-elect Donald Trump’s time in office, should the GOP hang on to control of the Senate after the 2026 midterm elections. 

Thune, 62, is currently the No. 2 GOP leader in the Senate, serving as majority whip beginning in 2020 and succeeding Cornyn, who was term-limited in the position. He has served as minority whip in the years when Republicans were not in control of the upper chamber.

Prior to winning the race to become the leader, Thune published an op-ed in Fox News about his commitment to advancing Trump’s campaign promises and unifying the Republican Party postelection. 

“We cannot afford to take this coalition for granted. If we fail to deliver on President Trump’s priorities, we will lose their support,” he wrote. “They have trusted us with their votes. Now we have to roll up our sleeves and get to work.”

Thune hinted at how he would plot the course for the Senate under his leadership, including ensuring Trump “has the necessary tools and support to enforce border security laws and to remove the violent criminals wreaking havoc in every state” and taking “a hatchet to the regulatory apparatus choking our economy.” 

He has pledged to hold regular meetings with House Speaker Mike Johnson (R-LA) to improve coordination with House Republicans and be in regular contact with Vice President-elect J.D. Vance to stay in sync with the Trump White House. In terms of how other entities may run with Thune in charge of the Senate, his previous stances on some matters may provide hints. 

In terms of judicial nominations, in 2016, he was unsupportive of former President Barack Obama’s nominee to the Supreme Court, who came seven months ahead of the 2016 election, saying it was too close to an election. In 2020, he switched his tune on this and supported an immediate vote on Trump’s nominee to fill the Supreme Court vacancy after Justice Ruth Bader Ginsburg’s death just two months before the election.

He and Trump have feuded over Thune’s refusal to go along with Trump’s efforts to subvert the 2020 election results. Thune, however, has worked on his relationship with Trump, having visited Mar-a-Lago in the spring and speaking with the president-elect ahead of the Senate leadership election.