"Now it is time for members of both parties to join together, put partisanship a side, and keep the American economic miracle going strong". And it made clear the extent to which Trump has remade his party to his own specifications, as he suggested that those who survived were indebted to him, a president who prizes loyalty above all else.
The new Democratic House majority will end Republican dominance in Washington for the final two years of Trump's first term with major questions looming about health care, immigration and government spending.
A Democratic House isn't going to put the U.S. back in the Iranian nuclear accord or the Paris climate agreement, and is unlikely to challenge Trump's protectionist line on trade.
"I can see it being extremely good politically", he said.
Hours earlier, the president had tweeted that "now we can all get back to work and get things done!"
He decried, as he often has for months, special counsel Robert Mueller's ongoing investigation into Trump 2016 campaign links to Russian Federation and whether Trump, as president, obstructed justice by trying to thwart the investigation. And if there's a total impasse, Trump said, "government comes to a halt and I would blame them". The alleged crime is attempted obstruction of justice, which Democrats will argue the president committed by interfering with a federal criminal investigation for venal - i.e., dishonest or self-protective - purposes.
It was "such a very Big Win", he tweeted, "and all under the pressure of a Nasty and Hostile Media!"
Trump has frequently been combative with reporters, and painted the news media as "enemies of the people", but Wednesdays press conference raised the level of his hostility. "You can't do them both", he said.
In ill-tempered exchanges, he called a CNN correspondent "a rude, bad person" and told an NBC reporter: "I'm not a big fan of yours either".
Ohio Rep. Tim Ryan, who ran against Pelosi a year ago as a centrist alternative, said colleagues want to do what's best for the new members coming from districts that just flipped from Republicans. He said he would be happy to help "supply her the necessary votes".
A Republican governorship majority coupled with GOP victories in gubernatorial races in battleground states may also boost Trump in 2020, since governors hold veto power over redistricting measures.
The Republicans are on course to increase their representation from 51 to 54 in the 100-seat Senate upper chamber.
Mr Trump also congratulated the new governor-elect of Florida Ron DeSantis, who fended off a challenge from the Democrats.
Democrats have promised to hold oversight hearings on the Trump administration when they take the majority in January.
President Trump also cited this as an area where he could work with Democrats in 2016, but nothing has happened to date.
The House Ways and Means Committee is expected to subpoena Mr Trump's long-hidden tax returns amid suspicions the billionaire has paid minimal amounts for years and possibly expose hidden foreign ties.
But control of the Senate ensures Mr Trump can still make key appointments.
Vilified by Republicans on the campaign trail, Nancy Pelosi emerged Wednesday as President Donald Trump's preferred choice to become speaker of the House, arriving on Capitol Hill with an air of inevitability after leading her party back to the majority.
Men, meanwhile, were about evenly split, with 50 percent voting for Republicans to 48 percent choosing Democrats.
Mr. Trump's comments angered Rep. Ryan A. Costello, a Pennsylvania Republican who is retiring this year.
But he did way better than then-President Barack Obama in his first midterm election.
The most likely impact of House investigations would be a swarm of legal issues for the White House, which is likely to fire up Trump's base for 2020 while producing no results to satisfy Democrat voters.
Democratic gains included several suburban districts eyed for turnover because they were won by Hillary Clinton, including seats outside Washington, Philadelphia, Miami and Denver.