2018 United States Senate election in California

The 2018 United States Senate election in California took place on November 6, 2018, to elect a member of the United States Senate to represent California, concurrently with other elections to the United States Senate, elections to the United States House of Representatives, and various state and local elections.

Under California's non-partisan blanket primary law, all candidates appear on the same ballot, regardless of party. In the primary, voters may vote for any candidate, regardless of their party affiliation. In the California system, the top two finishers — regardless of party — advance to the general election in November, even if a candidate receives a majority of the votes cast in the primary election. Washington and Louisiana have similar "jungle primary" style processes for U.S. Senate elections, as does Mississippi for U.S. Senate special elections.

The candidate filing deadline was March 8, 2018, and the primary election was held on June 5, 2018.

Democratic incumbent Dianne Feinstein won re-election in 2012 with 63% of the vote, taking the record for the most popular votes in any U.S. Senate election in history, with 7.86 million votes. Feinstein, at the time, was the ranking member of the Senate Judiciary Committee. She turned 85 years old in 2018, leading some to speculate that she would retire in January 2019, as her long-time colleague Barbara Boxer did in January 2017. However, Feinstein ran for re-election to her fifth full term, winning 44.2% of the vote in the top-two primary; she faced Democratic challenger Kevin de León in the general election, who won 12.1% of the primary vote. For the second time since direct elections to the Senate began after the passage of the Seventeenth Amendment in 1913, no Republican appeared on the general election ballot for the U.S. Senate in California. The highest Republican finisher in the primary won only 8.3 percent of the vote, and the 10 Republicans only won 31.2 percent of the vote among them. Briefly, during the early stages of the primary, Patrick Little, a Neo-Nazi running as a Republican polled at 18% which at the time put him in second place and the likely runoff candidate against Feinstein, however, his campaign collapsed after the media reported on his views.

In the general election, Feinstein defeated de León by an eight-point margin, 54% to 46%. This was Feinstein's closest election since 1994, as well as her last run for elected office, as she died in office in September 2023.

• Kevin de León, President pro tempore of the California State Senate

• Dianne Feinstein, incumbent U.S. Senator

• Adrienne Nicole Edwards, Vice Chairwoman on the HDT Community Development Foundation board

• Pat Harris, attorney

• Alison Hartson, national director of Wolf PAC

• David Hildebrand, legislative analyst

• Herbert G. Peters, retired aerospace engineer and candidate for U.S. Senate in California in 2016

• Douglas Howard Pierce

• Gerald Plummer

• Donnie O. Turner, Air Force veteran

• Topher Brennan

• John Melendez, television writer and radio personality

• Steve Stokes, candidate for the U.S. Senate in 2016

• Ana Kasparian, co-host of The Young Turks

• Joe Sanberg, entrepreneur and investor

• Tom Steyer, hedge fund manager

• Cenk Uygur, host of The Young Turks

• Arun K. Bhumitra, businessman

• James P. Bradley, businessman

• Jack Crew, bus driver

• Erin Cruz, published author

• Rocky De La Fuente, entrepreneur and perennial candidate

• Jerry Joseph Laws, candidate for the U.S. Senate in 2016

• Patrick Little, neo-Nazi and Holocaust denier (denounced by California Republican Party)

• Kevin Mottus, candidate for the U.S. Senate in 2016

• Mario Nabliba, scientist

• Tom Palzer, activist, retired city planner and candidate for the U.S. Senate in 2016

• Paul Allen Taylor, businessman

• Donald R. Adams, businessman

• Gary Coson

• John Estrada

• Timothy Charles Kalemkarian, perennial candidate

• Ernie Konnyu, former U.S. Representative

• Caren Lancona, businesswoman

• Jazmina Saavedra, businesswoman and activist

• Stephen James Schrader, veteran

• Kevin Faulconer, mayor of San Diego

• Caitlyn Jenner, 1976 Olympic gold medalist and television personality

• Arnold Schwarzenegger, actor and former Governor of California

• Ashley Swearengin, former mayor of Fresno

• Derrick Michael Reid, retired attorney and engineer and candidate for president in 2016

• Michael V. Ziesing (write-in)

• John Thompson Parker

• Colleen Shea Fernald, perennial candidate

• Rash Bihari Ghosh

• Tim Gildersleeve, businessman and researcher

• Michael Fahmy Girgis

• Don J. Grundmann, California Constitution Party chairman and perennial candidate (Constitution Party)

• Jason M. Hanania

• David Moore (Socialist Equality Party)

• Lee W. Olson

• Ursula M. Schilling (write-in)

• Ling Ling Shi, evangelist

• Jerry Leon Carroll

• Michael Eisen, biologist

• Charles Junior Hodge

• Richard Thomas Mead

• Clifton Roberts (Humane Party)

Primary results by county .mw-parser-output .legend{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .legend-color{display:inline-block;min-width:1.25em;height:1.25em;line-height:1.25;margin:1px 0;text-align:center;border:1px solid black;background-color:transparent;color:black}.mw-parser-output .legend-text{}  Feinstein   10–20%   20–30%   30–40%   40–50%   50–60%   60–70%   Feinstein/Bradley tie   10–20%

Democratic candidates won a combined total of 4,231,444 votes, Republican candidates 2,216,223 votes, and other candidates 223,053 votes.

• Complete video of debate, October 17, 2018

Because of California's top-two runoff system, the seat was guaranteed to be won/held by a Democrat since the initial primary produced two Democratic candidates.

The race had an undervote of around 1.3 million votes compared to the gubernatorial election, likely by Republican voters choosing neither candidate. De León won many of the same counties and congressional districts won by Republican gubernatorial nominee John Cox, as many voters may have expressed opposition to the incumbent senator. No county voted for both Feinstein and Cox. Congressional districts 39, 45, and 48 were the only congressional districts that voted for both Feinstein and Cox.

Blue represents counties won by Feinstein. Cyan represents counties won by de León.

Feinstein won 38 of the 53 congressional districts, with the remaining 15 going to De León, including seven held by Republicans.

• Candidates at Vote Smart
• Candidates at Ballotpedia
• Campaign finance at FEC
• Campaign finance at OpenSecrets

Official campaign websites

• Dianne Feinstein (D) for Senate Archived April 8, 2018, at the Wayback Machine
• Kevin de León (D) for Senate Archived October 15, 2017, at the Wayback Machine