Democrats have taken control of the House of Representatives in midterm elections in the United States, while Republicans gained seats that solidify their control of the Senate.
As of Wednesday morning, the Democrats were on track to win at least 26 seats previously held by Republicans, with several races still undecided, which could give them as many as 230 seats in the 435-seat chamber.
Among the winners were several first-time candidates, including two Native American women -- one of them openly gay -- and two Muslim women, a first in both categories. They will be among the 100 women who will be sworn in when the new Congress takes over in January, another first.
Speaking to a crowd of supporters in Washington Tuesday night, House Democratic Leader Nancy Pelosi said, "Thanks to you, tomorrow, there will be a new day in America."
The veteran California lawmaker, who served as the nation's first female House speaker from 2007-2011, said the victory was not about Democrats or Republicans, but about "restoring the Constitution's checks and balances to the Trump administration." Democrats will now be able to launch numerous investigations of President Donald Trump, including his personal finances and allegations of his presidential campaign's collusion with Russia to win the 2016 race.
WATCH: Election results
Despite the setback in the House, President Trump issued a self-congratulatory tweet Wednesday morning.
"Received so many Congratulations from so many on our Big Victory last night, including from foreign nations (friends) that were waiting me out, and hoping, on Trade Deals. Now we can all get back to work and get things done!"
"It is a critical check on Trump," says University of Virginia analyst Larry Sabato. "Big legislation with an ideological tint, left or right, won't pass for the next two years. Democrats now have the power of subpoena so Trump and his administration can expect to be investigated rather than protected by the House."
In the Senate, Republican challengers handily defeated Democratic incumbents in Indiana, Missouri and North Dakota, while two Republican challengers in Florida and Montana held razor-thin leads as vote counting stretched into Wednesday morning. The race for an open Senate seat in Arizona was also undecided.
In one of the most watched races, Republican Ted Cruz fended off a strong challenge from rising Democratic star Beto O'Rourke to keep his Senate seat in Texas.
And former Massachusetts Governor Mitt Romney, the 2012 Republican presidential nominee, easily won an open Senate seat in Utah. The Mormon-dominated state has embraced Romney, who is himself a Mormon. Romney also helped turn around the scandal-plagued 2002 Salt Lake City Winter Olympics.
Each of the 435 seats in the House was being contested, as were 35 of 100 Senate seats.
Precincts across the country reported strong voter numbers for a midterm election.
The New York Times and Michael McDonald of the United States Election Project both estimated national turnout of at least 111 million, far surpassing the 83 million people who voted in the 2014 midterms.
Rebecca Gill, an associate professor of political science at the University of Nevada, Las Vegas, said voter enthusiasm was the unusual aspect of Tuesday's election.
"This probably has something to do with some of the rhetoric, particularly from the president. It's been intended to rally his base, but at the same time, it ends up also rallying the base of the Democrats. It sort of polarizes folks, and it gets more people engaged on both sides," Gill said.