WASHINGTON—Republican senators chose John Thune of South Dakota as their first new leader in nearly two decades, opting for continuity over calls for radical change heading into populist President-elect Donald Trump’s second term in the White House.

U.S. Senate Republicans will gather behind closed doors on Wednesday to pick their next leader in the face of a public pressure campaign by supporters of President-elect Donald Trump who favor the long-shot bid of a hardline Trump loyalist.

Thune, of South Dakota, beat out Sens. John Cornyn of Texas and Rick Scott of Florida in a secret ballot election to replace Mitch McConnell in the top job.