Cornyn loses Senate majority leader race to Thune and becomes minority whip

Senate Republicans elected John Thune of South Dakota as Senate Majority Leader over John Cornyn of Texas in a 29-24 secret ballot vote, handing Cornyn a significant internal defeat. Cornyn had sought the top Senate leadership post after Mitch McConnell announced his retirement from leadership. The loss left Cornyn in a weakened institutional position heading into his 2026 reelection campaign, stripping him of the leverage that a majority leader title would have provided against a primary challenge.