Democrats in the House could be banking on launching an investigation using the results of U.S. Special Counsel Robert Mueller's already 18-month-old probe of allegations of Russian interference on Trump's behalf in the 2016 presidential election.
Democrats needed to pick up two dozen seats to seize the House majority and two seats to control the Senate.
The campaign unfolded against a backdrop of jarring political imagery, heated rhetoric and angry debates on immigration, health care and the role of Congress in overseeing the president.
Early in the evening, White House Press Secretary Sarah Sanders touted Trump's efforts during the campaign. With Democrats defeating Sessions and Culberson, they had a shot at at least 13 seats.
Voter turnout, normally lower when the presidency is not at stake, could be the highest for a midterm election in 50 years, experts predicted.
The Democrats, in turn, benefited from extraordinary voter enthusiasm, robust fundraising and unusually fresh candidates. More women than ever were running, along with military veterans and minorities, many of them motivated by Trump's rise.
Democrat Jennifer Wexton speaks at her election night party after winning in Virginia.
Since all such predictions were proven wrong in 2016, when Mr Trump won against all odds, no media outlet or opinion survey ruled out a surprise Republican win. He predicted an "invasion" from the migrant caravan making its way toward the USA and decried the "radical" agenda of speaker-in-waiting Pelosi. But, depending on the margin of victory for Democrats in the House, even that is unlikely to be immune to partisan obstruction.
But with his party losing its majority in the House, the results represented a bitter setback for Trump after a campaign that became a referendum on his leadership.
An American voter told SAMAA Digital that they live in a time where everything is not as trustworthy as it once was. Men, by contrast, were more divided in their vote.
Democrats, meanwhile, prioritized a different message in the midterms and heavily emphasized promises to safeguard health care for voters, including protecting individuals with pre-existing conditions.
They also promised to clean up government.
The result upends the balance of power in Washington, where Trump has enjoyed an easy ride from Republican dominance of both houses of Congress since his shock election in 2016. Joe Donnelly in a hard-fought race that saw Trump visit the Hoosier state several times in an attempt to flip the seat for the GOP.
In Virginia, political newcomer Jennifer Wexton defeated two-term GOP Rep. Barbara Comstock.
And outside Richmond, Virginia, one-time tea party favorite Rep. Dave Brat lost to Democrat Abigail Spanberger, a former Central Intelligence Agency operative motivated to run for office after the GOP vote to gut the Affordable Care Act. It has lost ground among women, suburban voters, voters with college degrees, while showing little ability to win over young and minority voters.
The swing in the House came as Democrats overcame gerrymandered districts in a number of states to win seats that in normal election years were out of their reach.
While Republican Ted Cruz was re-elected to Senate in Texas, Rashida Tlaib and Ilhan Omar became the first two Muslim women to be elected to the US Congress. Davids is also openly gay.
Democrats also successfully turned the GOP tax cuts into a net negative in many races, neutralizing an issue Republicans once hoped to run hard on by arguing the massive corporate cuts and tax breaks for wealthy Americans were helping rich people the most, and by fueling the federal deficit would lead Republicans to try to cut Social Security and Medicare in the near future.