Republicans have won enough seats to control the House of Representatives, completing the party’s sweep into power and securing their hold on both chambers of Congress and the White House

In yet another blow to Democrats, Donald Trump will begin his presidency with a trifecta of Republican control in Washington.

With a dozen races still to be called, the G.O.P. was two seats away from the 218 that would allow the party to claim a coveted governing trifecta: control of the House, Senate and White House.