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.

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.

U.S. Senate Republican leader John Thune faces the test of his career this year as he tries to steer Donald Trump's agenda through a narrowly divided Congress while protecting his own chamber's authority over Cabinet picks and spending.

The Senate gaveled in on Friday and officially came under Republican control, with newly elected Majority Leader John Thune (R-SD) being sworn in and vowing to preserve the filibuster, among other

Sen. John Thune used his first few minutes of floor time to make a commitment to defend the filibuster rule, which requires at least 60 votes to pass Senate legislation.

Republicans broadly support preserving the 60-vote threshold, which in most cases forces compromise to pass legislation through the Senate.