Senator John Thune said Friday that the filibuster has "perhaps the greatest impact in preserving the Founders' vision of the Senate."

New Senate Majority Leader John Thune is kicking off the new session with a promise to preserve the filibuster, saying in his first floor speech as leader that his priority will be to “ensure the Senate stays the Senate.

The affable traditional conservative from South Dakota is the first new chief of the Senate G.O.P. in nearly two decades. He will confront a challenge managing President-elect Donald J. Trump’s expectations.