The newly empowered House Democrats will have the ability to investigate Trump's tax returns, possible business conflicts of interest and allegations involving his 2016 campaign's links to Russia.
Voters often sit out the midterms, but this time, they stood up.
Time magazine called it "A High Water Mark for Midterm Turnout.' 2018 Could Be a Historic Election for Voter Participation."
According to estimates by The New York Times, approximately 114 million votes were cast in US House races in 2018. That's compared to 83 million in 2014.
Many describe this year's midterms as a surging, possibly record, turnout in the United States.
Snaking queues and long average wait times were reported as Americans voted on Tuesday for state governors, Senate seats and seats in the House of Representatives.
And on the streets, there was a palpable buzz.
"We have already seen huge turnout, people out and about knocking on doors, making sure everybody gets out there, but I think turnout will be very, very high," California's Democratic candidate Katie Porter said.
On the other side of the country, in Atlanta, Georgia, voters waited in line for nearly two hours to cast ballots, according to local media reports.
At a polling station in Arlington, Virginia, head election officer William Harkins said "it's a very good turnout."
Trump himself noted the energy as he wrapped up a punishing schedule of rallies around the country that were intended to boost Republican candidates and his own brand heading towards reelection in 2020.
"The midterm elections used to be, like, boring," Trump told a crowd in Cleveland, Ohio, on Monday. "Now it's like the hottest thing."
The Democratic gains were fueled by women, young and Hispanic voters, a Reuters/Ipsos Election Day poll found.
Fifty-five percent of women said they backed a Democrat for the House this year, compared to 49 percent in the 2014 midterm congressional election.
Voters between the ages of 18 and 34 backed Democrats by 62 percent to 34 percent, up from 2014 when 54 percent backed Democrats and 36 percent supported Republicans.
Hispanic voters favored Democratic House candidates by 33 percentage points - higher than the 18-percentage point gap that Democrats enjoyed in 2014, the poll found.
Democrats turned out to register disapproval of Trump's divisive rhetoric and policies on such issues as immigration and his travel ban targeting several Muslim-majority countries.
But clearly, the president also has a solid base of supporters, especially in rural areas as evident in the Senate where Republicans increased their majority.