The Democratic Party will keep control of the US Senate, multiple networks projected on Saturday night.
The battle for the House, meanwhile, remains too close to call.
The picture in the Senate became clear on Saturday after Democratic Sen. Catherine Cortez Masto of Nevada narrowly defeated Republican Adam Laxalt to win re-election, putting her party over the threshold, NBC News projected.
Her victory gave the party the 50 seats they need for an effective majority.
Democratic Sen. Mark Kelly of Arizona won his re-election contest in Arizona, NBC News projected Friday evening.
One race is still undecided, as Georgia’s race between Democratic Sen. Raphael Warnock and Republican challenger Herschel Walker is headed to a December runoff, after neither candidate cleared the required 50% threshold in Tuesday’s vote.
Even if Republicans win the Georgia runoff, however, Vice President Kamala Harris would continue to have the tie-breaking vote in an evenly divided Senate to guarantee the Democratic majority.