Democrats will keep control of the Senate next year, with Democratic Sen. Catherine Cortez Masto projected as the winner in a tight race in Nevada Saturday night.
Ms. Cortez Masto narrowly defeated Republican challenger Adam Laxalt, according to projections by CNN and NBC.
Her victory gives Democrats at least 50 seats in the Senate next year.
The outcome of the lone remaining Senate race, in Georgia, will be decided in a runoff next month between incumbent Democratic Sen. Raphael Warnock and Republican challenger Herschel Walker.
Democrats currently hold the tie-breaking vote in the Senate with Vice President Kamala Harris.
The win is a stunning result for Democrats and President Biden in the midterm election when the party holding the White House usually loses seats in congress. Republicans were already engaged in finger-pointing about their disappointing performance before Ms. Cortez Masto was declared the winner.
Nevada’s vote-counting dragged on for four days since Tuesday’s election, drawing heavy criticism amid predictions by many Republicans that Mr. Laxalt would pull out a win.
Control of the House is still undecided, although Republicans currently lead in the number of seats, 211 to 204, per CNN.