Ruben Gallego (D), Kari Lake (R), and Eduardo Quintana (G) are running in the general election for United States Senate in Arizona on Nov. 5, 2024.

Political observers including Simone Pathe of CNN, Jonathan Weisman of The New York Times, Sara Dorn of Forbes, and Lucas Wright of USA Today say this election will be among the closest for U.S. Senate nationwide. Recent statewide elections in Arizona have been competitive—of the 23 statewide elections held in Arizona between 2018 and 2022, Republicans won 12 and Democrats won 11.

As of Sept. 10, 2024, the five most recent polls Ballotpedia tracked included four showing Gallego with a lead outside the margin of error—one showing him up 56%–41% with a 3.0% margin of error and one showing him up 47%–40% with a 3.1% margin of error. Additional polls showed Gallego leading 49%–42% with a 3.6% margin of error 49%–45% with a 3.0% margin of error. A fifth poll showed the two about even, with Gallego at 47% and Lake at 44% with a 4.8% margin of error. Gallego has raised $32,349,690 and Lake has raised $10,371,320. As of the same date, Decision Desk HQ and The Hill rated the election as Likely Democratic, The Cook Political Report with Amy Walter and Larry J. Sabato’s Crystal Ball rated it Lean Democratic, and Inside Elections with Nathan L. Gonzales rated it Tilt Democratic.

Gallego is a member of the U.S. House, former state legislator, and a U.S. Marine Corps veteran. Gallego says he is running “to defend our Democracy, hold corrupt politicians accountable, and preserve a woman’s right to have an abortion.” Gallego says he “took advantage of the things Democrats championed and the people of our country provided: Pell Grants and school lunch programs to name two,” and that his political and military service is an opportunity to repay that debt.

Lake is a former newscaster who ran for governor in 2022. Lake says she believes in “secure borders, energy independence, safe streets, education not indoctrination, pushing back against the radical Biden agenda, and preserving the western heritage that makes Arizona special.” Lake says she is running because of “a socialist Democrat Party that has lost touch with reality, a corrupt president who has lost touch with his brain, and we’re sick of the swamp putting the rest of the world first.”

The outcome of this race will affect the partisan balance of the U.S. Senate in 2025.

Thirty-four of 100 seats are up for election, including one special election. Of the seats up for election in 2024, Democrats hold 19, Republicans hold 11, and independents hold four. As of May 2024, eight members of the U.S. Senate had announced they were not running for re-election.

Incumbent Kyrsten Sinema (Independent) is not running for re-election. This is one of eight open races for the U.S. Senate in 2024 where an incumbent is not running for re-election. Across the country, four Democrats, two Republicans, and two Independents are not running for re-election. In 2022, six Senators did not seek re-election, including one Democrat and five Republicans.