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.
What's the single most important issue among voters? Who do they trust to handle inflation? For ABC News' analysis of preliminary exit poll results, head here throughout the night.
Polling hours vary from state to state, and sometimes district to district within a state.
Here's a timeline of when the last polls close by state, all ET:
7 p.m.: Georgia, Indiana, Kentucky, South Carolina, Vermont, Virginia (polls close in some parts of Indiana and Kentucky at 6 p.m. ET)
7:30 p.m.: North Carolina, Ohio, West Virginia
8 p.m.: Alabama, Connecticut, Delaware, D.C., Florida, Illinois, Maine, Maryland, Massachusetts, Mississippi, Missouri, New Hampshire, New Jersey, Oklahoma, Rhode Island, Tennessee
8:30 p.m.: Arkansas
9 p.m.: Arizona, Colorado, Iowa, Kansas, Louisiana, Michigan, Minnesota, Nebraska, New Mexico, New York, North Dakota, South Dakota, Texas, Wisconsin, Wyoming
10 p.m.: Montana, Nevada, Pennsylvania, Utah
Polling location hours were extended from 8 p.m. to 10 p.m. in Luzerne County
11 p.m.: California, Idaho, Oregon, Washington
Midnight: Hawaii
1 a.m.: Alaska
The 2022 election could usher in many historic firsts.
Two women could make history as the nation’s first Black female governor: Stacey Abrams, who is running in Georgia, and Deidre DeJear, who is on the ballot in Iowa.
Democrat Val Demings could become the first Black senator to represent Florida and the third Black woman elected to the Senate. There are currently no Black women in the Senate. Democrat Cheri Beasley could become the first Black person to represent North Carolina in the Senate and the third Black woman elected to Senate.
New York Gov. Kathy Hochul would become the first woman elected governor in the state if she wins. (Hochul was appointed to her current role when Andrew Cuomo resigned over sexual harassment allegations, though he denied intentionally harming anyone.)
Sarah Huckabee Sanders could become the first woman elected governor of Arkansas and Katie Britt could become Alabama’s first woman elected to the Senate.
Rep. Karen Bass, D-Calif., could become the first woman elected mayor of Los Angeles.
If elected, Wes Moore would be Maryland’s first Black governor, while Mandela Barnes could become the first Black Senator to represent Wisconsin.
Madison Horn of Oklahoma could be the first Native American woman in the Senate while Yesli Vega could be the first Latina to represent Virginia.
Karoline Leavitt, a Republican candidate for New Hampshire's 1st Congressional District, could become the first member of Gen Z elected to Congress and the youngest Republican female elected to Congress. Maxwell Frost, a Florida Democrat, could also become the first member of Gen Z elected to Congress.
Maura Healey is poised to become the first woman and first openly lesbian politician elected governor of Massachusetts as well as the first openly lesbian governor in U.S. history, while Tina Kotek could be the first openly lesbian politician elected governor of Oregon and, like Healey, could be the first openly lesbian governor in U.S. history.
Eric Sorensen, if elected, would be the first openly gay congressman to represent Illinois.
In New York’s 3rd Congressional District, both candidates from the major parties are openly gay men: Democrat Robert Zimmerman and Republican George Devolder-Santos. Whoever wins will become the first openly gay person to represent Long Island in the House.
-ABC News’ Hannah Demissie and Averi Harper
Two Fulton County, Georgia, poll workers -- a mother and son -- were fired moments before polls opened Tuesday because they allegedly shared social media posts of a “threatening” nature, Fulton County spokeswoman Regina Waller told ABC News.
The Washington Post reported that the mother said she attended the Jan. 6 rally at the Capitol.
-ABC News’ Lucien Bruggeman
