Republicans retain majority in the US House, giving Donald Trump and his party unified control of the elected branches of government.
The Republican sweep limits potential curbs on Trump's power and strengthens their hand to enact immigration controls and reduce regulations.
The GOP will hold at least 218 seats in the 435-member chamber starting January, removing the threat of congressional investigation of Trump's actions by Democrats.
The House Republican majority will be razor-thin and intra-party divisions threaten unified actions, but Trump may have more leverage with conservative hardliners.