A unified Republican grip on Washington would set the course for Trump's agenda. Or if Democrats wrest control of the House, it would provide an almost certain backstop, with veto power over the White House.
Trump, speaking early Wednesday at his election night party in Florida, said the results delivered an “unprecedented and powerful mandate” for Republicans.
He called the Senate rout “incredible.” And he praised House Speaker Mike Johnson, who dashed from his own party in Louisiana to join Trump. “He's doing a terrific job,” Trump said.
Vote counting in some races could go on for days, and control of the House is too early to call.
The rally for Republicans started early on election night in West Virginia, when Jim Justice, the state's governor, flipped the seat held by retiring Sen. Joe Manchin. From there, the Republicans marched alongside Trump across the Senate map.
Republicans toppled Democrat Sen. Sherrod Brown in Ohio, the first incumbent senator to fall, with GOP luxury car dealer and blockchain entrepreneur Bernie Moreno. They chased Democrats in the “blue wall” states of Pennsylvania, Michigan and Wisconsin, where Vice President Kamala Harris strained to carry the party forward.
Democratic efforts to oust firebrand Republicans ted Cruz of Texas and Rick Scott of Florida collapsed. The unexpected battleground of Nebraska pushed Republicans over the top. Incumbent GOP Sen. Deb Fischer brushed back a surprisingly strong challenge from independent newcomer Dan Osborn.
One of the most-watched Senate races, in Montana, was decided early Wednesday. Democrat Jon Tester, a popular three-term senator and “dirt farmer” in the fight of his political career lost to Trump-backed Tim Sheehy, a wealthy former NAVY Seal.
The fight for control of the House became a state-by-state slog, much of which unfolded far from the presidential race.
House races are focused in New York and California, where Democrats are trying to claw back some of the 10 or so seats where Republicans have made surprising gains in recent years.
Other House races are scattered around the country, with some of the most contentious in Maine, the “blue dot” around Omaha, Nebraska, and in Alaska.
To gain control of the House, Democrats need to flip four seats from Republicans, while holding all of their own, a tall task especially in congressional districts where Trump has won.
It could come down to just a handful of seats, or as little as one, to determine House control.