The Democrats have taken control of the US House of Representatives in the mid-term elections, dealing a blow to President Donald Trump.
A Democratic majority in the lower chamber for the first time in eight years will restrict his ability to steer his programme through Congress.
But Mr Trump's Republicans are set to strengthen their grip on the Senate.
Tuesday's vote was seen as a referendum on a polarising president, even though he is not up for re-election till 2020.
The election confirms a historical trend for the party that is not in the White House to make gains in the mid-terms.
House Democratic leader Nancy Pelosi – who is set to become speaker, a position she held from 2007 to 2011 – told cheering supporters in Washington: "Thanks to you, tomorrow will be a new day in America."
What difference does the new House majority make?
The Democrats took control of the House, having gained more than the 23 seats they need to take over the lower chamber of Congress. Americans voted for all 435 seats in the House.
The Democrats could now launch investigations into Mr Trump's administration and business affairs, from tax returns to potential conflicts of interest.
They could also more effectively block his legislative plans, notably his signature promise to build a wall along the border with Mexico.
Female candidates performed particularly well in an election cycle that had been billed as the Year of the Woman.
Two 29-year-old Democrats, Alexandria Ocasio-Cortez and Abby Finkenauer – are due to be the youngest women ever to win House seats.
Ilhan OImar and Rashida Tlaib are the first Muslim women and Sharice Davids and Debra Haaland the first Native American women to be elected to Congress. All are Democrats.
What's happening in the Senate?
Republicans are on course to increase their representation in the 100-seat Senate from 51 to 54. This ensures Mr Trump will still have a majority to confirm his executive and judicial appointments.
Democrats were always facing an uphill battle in the Senate this year because they were defending 26 races, while just nine Republican seats were up for grabs.
Key gains for the Republicans came in Indiana, Missouri and North Dakota, where they unseated Democrat incumbents.
Rick Scott is likely to defeat a Democratic incumbent in Florida, giving Republicans control of both the state's seats for the first time in more than a century.
Republican Texas Senator Ted Cruz fended off a strong challenge by Democratic rising star Beto O'Rourke.