"Americans have had enough of division;" declared the Democrat house leader Nancy Pelosi as the result became clear.
This is the first time in eight years that the Democrats will have the upper hand in the House, enabling them to challenge Trump's agenda.
Just after polls closed on the West Coast, Trump took to Twitter to hail his party's performance calling the midterms "a tremendous success", clearly pleased his Republican Party expanded its Senate majority.
Pelosi, who is likely to return as speaker of the House despite opposition from some centrist Democrats, promised that the party will serve as a counterweight but also work with Trump.
"Today is more than about Democrats and Republicans. It's about restoring the constitution's checks and balances to the Trump administration," Pelosi told a news conference.
Democrats' Senate disappointment
“At a minimum, the Democrats had to recapture control of the House, to be able to block Donald Trump’s agenda or the Republican agenda to hold the administration to greater accountability for its actions," former US diplomat William Jordan told RFI. "It was critical for the Democrats credibility to be able to get the House.
“What has been less positive is how badly I think they’ve done in the Senate. They’ve not only failed to hold onto the seats that they should’ve held on to but they have also lost seats."
But the Democrat losses have not been high enough to give the Republicans the 60 votes that would give them a free hand in the Senate.
There were also important races for state governorships.
“What I was counting on the most for the Democrats was to equalise the governorships in the country," Jordan commented. "What is often not understood overseas is just how important governorships are in the United States to setting the stage for national elections, whether you’re talking about redefining electoral districts or setting the rules for voter registration as well as voter ID. These are all things that have been very important and very critical in this latest election."
The Democrats failed to win the seven governorships they hoped for actually lost some of them, Jordan pointed out.
Racially charged campaign
The midterms came after a polarising, racially charged campaign.
One of the key issues for Trump was the crackdown on illegal immigrants.
Claiming that the country faces an "invasion" of migrants, Trump has sent thousands of soldiers to the Mexican border.
Stirring fear of foreigners and trumpeting American nationalism worked for Trump in his 2016 election victory against the Democrats' establishment candidate Hillary Clinton.
But the angry tone has also turned off swaths of Americans.
Virginia, traditionally staunchly Republican, this year swung to the Democrats.
Over the past year, the mood in Virginia changed, particularly since a demonstration by white supremacists in the city of Charlottesville last August which turned violent.
Trump's failure to openly condemn the attack which saw one protester killed, was widely judged to have emboldened the country's far-right, racist fringe.
Tim Kaine, who was Hillary Clinton's running mate in the 2016 presidential race soundly defeated his Republican challenger Corey Stewart in Virginia, a Trumpian opponent who fell under sharp criticism for his links to far-right figures.
Women, minorities, left
It has been good news for women and minorities:
- Democratic left-winger Alexandria Ocasio-Cortez made history as the youngest woman elected to Congress, riding a wave of minority women taking office;
- Muslim woman Ilhan Omar, a Somali refugee, won a House seat in a district in the Midwestern state of Minnesota;
- Rashida Tlaib, a social worker born in Detroit to Palestinian immigrant parents, won a House seat in a district of Michigan, where she ran unopposed by the Republicans;
- Kansas Democrat Sharice Davids, an attorney and former mixed martial arts fighter, became the first native American woman elected to Congress, defeating Republican incumbent Kevin Yoder;
- Deb Haaland, a member of the Pueblo of Laguna tribe of New Mexico, beat Janice Arnold-Jones, a Republican.
Districts around the country also reported unusually high turnout: according to Michael McDonald of the US Elections Project, 38.4 million Americans cast their ballots early ahead of this election, compared with 27.4 million in the 2014 midterm.