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.
ABC News can project that no candidate in the Alaska Senate race will receive 50% of the first-choice votes. Incumbent Rep. Lisa Murkowski and Kelly Tshibaka, both Republicans, have advanced to the next round of ranked-choice voting, with the winner to be announced on Nov. 23.
Rep. Cindy Axne, D-Iowa, has conceded in her bid for reelection, flipping the state's 3rd Congressional District.
"Even though the numbers weren't in our favor this year, I encourage you all to continue to have the hard conversations with your friends and your neighbors about the issues that matter," she wrote on Twitter, shortly before ABC News projected that Republican state Sen. Zach Nunn will win the seat.
With Axne out, there will be no Democrats representing Iowa in Congress next year.
-ABC News' Hannah Demissie
President Joe Biden said he intends to run for reelection, though he said he doesn't plan to make a formal decision with first lady Jill Biden until early next year.
"Our intention is to run again," Biden told reporters Wednesday during remarks on the midterms. "That's been our intention, regardless of what the outcome of this election was."
Biden said he and his family are going to have "discussions" about it over the next few weeks.
"My intention is that I will run again, but I'm a great respecter of fate, and this is ultimately a family decision," he said.
"I don't feel in any hurry one way or another to make that judgment. Today, tomorrow, whenever, no matter what my predecessor does," he added, not referring to former President Donald Trump by name.
Sources told ABC News that Trump, who has been teasing a "big announcement," could potentially announce a 2024 presidential run as early as the week of Nov. 14.
Even as some key races are still outstanding, President Joe Biden addressed Democrats' stronger-than-expected midterms results.
"It was a good day, I think, for democracy. And I think it was a good day for America," Biden told reporters during an address from the White House on Wednesday.
Biden said that "any seat lost is painful" while acknowledging that some Democrats didn't win their elections. But overall he said the party "had a strong night."
"We lost fewer seats in the House of Representatives than any Democratic president's first midterm election in the last 40 years," he said.
Read more about Biden's address here.
