The Democrats have taken control of the House of Representatives. The GOP, meanwhile, kept control of the U.S. Senate.
Democrats last had a majority in the House in 2010. With their victory on Tuesday, Democrats will take over the leadership of key committees that could launch numerous investigations into the Trump White House.
Democratic candidates had fundraising advantages in dozens of close contests heading into Election Day. Republicans had hoped that a strong economy and Mr. Trump's ability to turn out base voters would be enough to overcome high levels of enthusiasm among Democratic voters. But in the end Democrats triumphed, ending a brief era of unified Republican government.
Tuesday night's House results are a much-needed boost for the Democrats, who have struggled in a string of midterm elections. Republicans won the House in 2010 and retook the Senate in 2014. Hillary Clinton's 2016 loss to Mr. Trump, coupled with the GOP's ability to retain control of Congress that year, also stunned the Democratic faithful.
On the Republican side, Paul Ryan's retirement is likely to set off a struggle for minority leader. GOP Reps. Kevin McCarthy, Jim Jordan and Steve Scalise are all potential contenders for the position. Ryan has already endorsed McCarthy to succeed him, but some conservatives have said they would prefer that Jordan lead the conference.