Catherine Cortez Masto’s victory in Nevada clinched the chamber for Democrats.
The 2022 midterm elections shaped up to be some of the most consequential in the nation's recent history, with control of Congress at stake.
All 435 seats in the House and 35 of 100 seats in the Senate were on the ballot, as well as several influential gubernatorial elections in battleground states like Arizona, Georgia, Pennsylvania and Wisconsin.
Democrats were defending their narrow majorities in both chambers and retained control of the Senate, though control of the House isn't yet clear. But a Republican flip of the lower chamber would be enough to curtail most of President Joe Biden's legislative agenda and would likely result in investigations against his administration and even his family.
Rep. Sean Patrick Maloney of New York on Wednesday called his Republican challenger Mike Lawler to concede. Political insiders say this was a big loss for Democrats.
Maloney is the chairman of the Democratic Congressional Campaign Committee, the fundraising arm for the House. He directed millions to save his own campaign and insisted he wasn’t in real trouble, potentially costing his colleagues votes.
-ABC News’ Rick Klein and Aaron Katersky
Democrat Laura Kelly, the incumbent, is projected to win the Kansas gubernatorial race.
Her opponent, Kansas Attorney General Derek Schmidt, was backed by former President Donald Trump.
While former President Donald Trump still has a hold over Republicans and prepares to announce his candidacy for president in 2024, election night was not a "red wave" as Trump had expected.
Sources close to the former president described him as fuming, especially as candidates Trump backed performed poorly with voters.
Gov. Ron DeSantis' successful night in Florida also served as a wakeup call for Trump and his advisers.
"This is a sinking ship," one top Trump adviser told ABC News. "We're not going to beat that."
“This was the end of the Trump era and the dawn of the DeSantis era. Like every other Trump catastrophe, he did this to himself with stupid and reckless decisions,” a Republican operative close to the Trump orbit told ABC News.
Trump suffered losses across the country and was particularly unhappy as he watched two candidates he endorsed in Pennsylvania lose their elections: Senate candidate Dr. Mehmet Oz and gubernatorial candidate Doug Mastriano.
Trump told advisers he was also shocked the Georgia Senate race between incumbent Democratic Sen. Raphael Warnock and challenger Republican Herschel Walker was so close. (On Wednesday morning, with 96% of the expected vote reporting, Warnock and Walker were tied at 49%.)
Trump announced on Monday that he planned to make a big announcement next week. Some of those close to Trump are privately hoping that he decides not to run. But others who have spoken with him say he's unlikely to renege on his plans because he's spent the last two years teasing a run.
-ABC News’ Katherine Faulders, John Santucci, Olivia Rubin and Will Steakin
Pennsylvania's Dr. Mehmet Oz called Democrat Lt. Gov. John Fetterman at 9:30 a.m. Wednesday to concede, according to a tweet from Fetterman’s communications director.
Oz "was nothing but class" and wished Fetterman "all the best," Fetterman spokesman Joe Calvello told ABC News.
Fetterman was projected to win Pennsylvania's Senate race, one of the most closely watched races in the nation.
