The Democrats looked poised to take control of the US House of Representatives for the first time in eight years in the first major election since Donald Trump was elected president, but the Republicans were poised to hold the Senate.
In the one of the most eagerly-anticipated US midterm elections in recent memory, the Democrats were on course to gain the 23 seats they needed to capture the Republican-held House.
The BBC, CNN, NBC, ABC News and Fox News were among the broadcasters to project a Democrat victory, which is seen as crucial to the party checking Trump’s agenda.
But slim hopes of capturing the Senate and sealing a ‘blue wave’ looked unlikely after Republicans made gains and looked set to hold firm.
Some of the biggest Democratic stars of the campaign season were struggling, with Beto O’Rourke’s underdog US Senate campaign to oust Ted Cruz in conservative Texas failing.
Trump has spoken of a “tremendous success” after the Republican party retained control of the Senate.
With a House majority, Democrats will have the power to investigate Trump’s tax returns and possible conflicts of interest, and challenge his overtures to Saudi Arabia, Russia and North Korea.
They also could force Trump to scale back his legislative ambitions, possibly dooming his promises to fund a border wall with Mexico, pass a second major tax-cut package or carry out his hardline policies on trade.
A simple House majority would be enough to impeach Trump if evidence surfaces that he obstructed justice or that his 2016 campaign colluded with Russia. But Congress could not remove him from office without a conviction by a two-thirds majority in the Republican-controlled Senate.
A record number of women ran for office this election, many of them Democrats turned off by Trump’s policy agenda.
In the House, Democrats picked up seats across the map, ousting incumbent Republican Barbara Comstock in suburban Virginia and sending Donna Shalala, a former Cabinet secretary under President Bill Clinton, to the House in south Florida.
In the Senate, where Republicans were heavily favoured to keep control heading into Tuesday’s voting, Republican Mike Braun captured incumbent Joe Donnelly’s seat in Indiana and Republican Kevin Cramer beat incumbent Democratic Senator Heidi Heitkamp in North Dakota.
But Andrew Gillum was trailing Republican Ron DeSantis in his quest to become the first African-American governor of the key swing state of Florida.
In other notable contests, Democrat Alexandria Ocasio-Cortez won her race for a US House seat in New York – becoming, at 29, the youngest woman ever elected to Congress.
Colorado voters elected Jared Polis, making him the first openly gay man elected governor in the United States.
The volatile midterm campaign was marked by clashes over race, immigration and trade. In the final stretch, Trump hardened his rhetoric on issues that appealed to his conservative core supporters, issuing warnings about a caravan of Latin American migrants headed to the border with Mexico and condemnations of what he called US liberal “mobs”.