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.

Senate Majority Leader John Thune revealed to the Daily Caller News Foundation Monday that the Senate has chosen to crack

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.