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.

It also leaves Democrats with less leverage to challenge policies they disagree with, though narrow margins mean Senate Republicans could still struggle to secure enough votes for

Republicans held on to their narrow majority in the US House, giving Donald Trump and his party unified control of the elected branches of government and limiting potential curbs on the incoming president’s power.