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.

Candidates

Democratic Party

Advanced to general

Eliminated in primary

  • 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

Withdrawn

  • Topher Brennan
  • John Melendez, television writer and radio personality
  • Steve Stokes, candidate for the U.S. Senate in 2016

Declined

Republican Party

Declared

  • 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

Withdrawn

  • 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

Declined

Libertarian Party

Declared

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

Green Party

Declared

  • Michael V. Ziesing (write-in)

Peace and Freedom Party

Declared

  • John Thompson Parker

No party preference

Declared

  • 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

Withdrawn

  • Jerry Leon Carroll
  • Michael Eisen, biologist
  • Charles Junior Hodge
  • Richard Thomas Mead
  • Clifton Roberts (Humane Party)

Notes

Primary election

Endorsements

U.S. presidents

U.S. vice presidents

U.S. Senators

U.S. Representatives

State officials

Local officials

Organizations

Newspapers

Individuals

  • Tom Steyer, billionaire, hedge fund manager, philanthropist, environmentalist, liberal activist, and fundraiser

U.S. Representatives

State officials

Local officials

Organizations

Organizations

  • F.U.N. Progressives
  • Tri-Valley Democratic Club

Individuals

Individuals

Organizations

  • California for Bernie 2020
  • Demand Universal Healthcare
  • Justice Democrats
  • Our Revolution Lake County
  • Our Revolution San Joaquin County
  • Our Revolution West Marin
  • ProgressivesUnite
  • The Young Turks

Local officials

  • Vinnie Bacon, Vice Mayor of Fremont, Fremont City Council member
  • Jovanka Beckles, former Richmond City Council member, candidate for the State Assembly - District 15
  • Gayle McLaughlin, former Mayor of Richmond, candidate for Lieutenant Governor
  • Porsche Middleton, Citrus Heights Planning Commissioner, candidate for the Citrus Heights City Council
  • Noah Phillips, Deputy District Attorney for Sacramento County, candidate for Sacramento County District Attorney

Individuals

  • Michael Bracamontes, civil rights attorney, former candidate for California governor
  • Stephen Jaffe, employment attorney, candidate for U.S. Congress
  • Kevin Murray, professor of politics, Humboldt State University
  • Stephen Seager, mental health expert, author, documentary filmmaker

Organizations

  • Bernie Sanders Megagroup 2020
  • Candidates with a Contract
  • Courageous Resistance of Humboldt - Our Revolution
  • Feel the Bern Democratic Club of Los Angeles
  • Labor Campaign for Single Payer
  • Not Me Us - We are the Revolution
  • Our Revolution West Marin
  • The People's News
  • Stanislaus County for Bernie 2020
  • Ventura County Activists for Bernie Sanders 2020 #OurRevolution
  • Wellstone Progressive Democrats of Sacramento - Our Revolution
  • Yolo County Progressives - Our Revolution

Individuals

Individuals

Organizations

Politicians

  • David Duke, white nationalist and former Louisiana State Representative

Organizations

Organizations

Fundraising

Campaign finance reports as of May 16, 2018
CandidateTotal receiptsTotal disbursementsCash on hand
Dianne Feinstein (D)$9,953,612$5,342,658$7,035,307
Kevin de León (D)$1,135,538$441,847$693,689
Pat Harris (D)$703,982$650,225$51,017
Alison Hartson (D)$298,296$189,652$108,643
Arun K. Bhumitra (R)$53,668$40,835$12,832
David Hildebrand (D)$27,111$25,816$1,294
Erin Cruz (R)$26,442$23,190$3,251
Douglas Howard Pierce (D)$9,000$62,392$11,200
Paul Allen Taylor (R)$9,128$8,803$324
Tom Palzer (R)$0$45$45
David Moore (SEP)$3,480$3,480$0
Source: Federal Election Commission

Polling

Poll sourceDate(s) administeredSample sizeMargin of errorJames P. Bradley (R)Erin Cruz (R)Pat Harris (D)Rocky De La Fuente (R)Kevin de León (D)Dianne Feinstein (D)Alison Hartson (D)Patrick Little (R)Other / Undecided
UC BerkeleyMay 22−28, 20182,106± 3.5%7%–––11%36%––46%
Emerson CollegeMay 21–24, 2018600± 4.2%–5%6%4%6%38%4%–38%
YouGovMay 12–24, 20181,113± 4.0%6%2%2%4%11%36%1%1%37%
SurveyUSAMay 21, 2018678± 6.1%9%2%2%3%11%36%1%0%35%
Public Policy Institute of CaliforniaMay 11–20, 2018901± 4.1%––––17%41%––41%
USC Dornsife/Los Angeles TimesApril 18 – May 18, 2018517± 4.0%3%1%2%0%7%31%1%2%51%
Gravis MarketingMay 4–5, 2018525± 4.3%19%13%––8%32%6%–21%
SurveyUSAApril 19–23, 2018520± 5.5%–––8%8%38%4%18%23%
UC BerkeleyApril 16–22, 20181,738± 3.5%10%–––11%28%––49%
Public Policy Institute of CaliforniaMarch 4–13, 20181,706± 3.4%––––16%42%––41%
Public Policy Institute of CaliforniaJanuary 21–30, 20181,705± 3.2%––––17%46%––36%
UC BerkeleyDecember 7–16, 2017672± 3.8%––––27%41%––32%
Public Policy Institute of CaliforniaNovember 10–19, 20171,070± 4.3%––––21%45%––34%
Sextant Strategies & ResearchSeptember 20171,197± 3.4%––––15%38%––46%

with Timothy Charles Kalemkarian, Caren Lancona, John Melendez, and Stephen Schrader

Poll sourceDate(s) administeredSample sizeMargin of errorKevin de León (D)Dianne Feinstein (D)Timothy Charles Kalemkarian (R)Caren Lancona (R)Patrick Little (R)John Melendez (D)Stephen Schrader (R)Other / Undecided
SurveyUSAMarch 22–25, 2018517± 5.0%5%31%5%2%5%5%7%42%
SurveyUSAJanuary 7–9, 2018506± 4.4%4%34%6%5%5%2%5%38%

with Tom Steyer

Poll sourceDate(s) administeredSample sizeMargin of errorKevin de León (D)Dianne Feinstein (D)Timothy Charles Kalemkarian (R)Caren Lancona (R)Patrick Little (R)Tom Steyer (D)Other / Undecided
SurveyUSAJanuary–9, 2018506± 4.4%3%29%5%5%5%5%46%

with John Cox

Poll sourceDate(s) administeredSample sizeMargin of errorJohn Cox (R)Kevin de León (D)Dianne Feinstein (D)Undecided
Sextant Strategies & ResearchSeptember 20171,197± 3.4%32%14%40%14%

with Xavier Becerra, Kevin Faulconer, Brad Sherman, Eric Swalwell, and Ashley Swearingin

Poll sourceDate(s) administeredSample sizeMargin of errorXavier Becerra (D)Kevin de León (D)Kevin Faulconer (R)Brad Sherman (D)Eric Swalwell (D)Ashley Swearingin (R)Undecided
Public Policy PollingJanuary 17–18, 2017882± 3.3%21%4%18%11%5%13%28%

Results

Primary results by county Feinstein 10–20%20–30%30–40%40–50%50–60%60–70% Feinstein/Bradley tie 10–20%
Nonpartisan blanket primary results
PartyCandidateVotes%
DemocraticDianne Feinstein (incumbent)2,947,03544.12%
DemocraticKevin de León805,44612.07%
RepublicanJames P. Bradley556,2528.34%
RepublicanArun K. Bhumitra350,8155.26%
RepublicanPaul A. Taylor323,5334.85%
RepublicanErin Cruz267,4944.01%
RepublicanTom Palzer205,1833.08%
DemocraticAlison Hartson147,0612.21%
RepublicanRocky De La Fuente135,2782.03%
DemocraticPat Harris126,9471.90%
RepublicanJohn "Jack" Crew93,8061.41%
RepublicanPatrick Little89,8671.35%
RepublicanKevin Mottus87,6461.31%
RepublicanJerry Joseph Laws67,1401.01%
LibertarianDerrick Michael Reid59,9990.90%
DemocraticAdrienne Nicole Edwards56,1720.84%
DemocraticDouglas Howard Pierce42,6710.64%
RepublicanMario Nabliba39,2090.59%
DemocraticDavid Hildebrand30,3050.45%
DemocraticDonnie O. Turner30,1010.45%
DemocraticHerbert G. Peters27,4680.41%
No party preferenceDavid Moore24,6140.37%
No party preferenceLing Ling Shi23,5060.35%
Peace and FreedomJohn Thompson Parker22,8250.34%
No party preferenceLee Olson20,3930.31%
DemocraticGerald Plummer18,2340.27%
No party preferenceJason M. Hanania18,1710.27%
No party preferenceDon J. Grundmann15,1250.23%
No party preferenceColleen Shea Fernald13,5360.20%
No party preferenceRash Bihari Ghosh12,5570.19%
No party preferenceTim Gildersleeve8,4820.13%
No party preferenceMichael Fahmy Girgis2,9860.05%
GreenMichael V. Ziesing (write-in)8420.01%
No party preferenceUrsula M. Schilling (write-in)170.00%
DemocraticSeelam Prabhakar Reddy (write-in)40.00%
Total votes6,670,720100.00%

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

General election

Debates

  • , October 17, 2018

Endorsements

Former Executive Branch officials

U.S. Senators

U.S. Representatives

State officials

Local officials

Organizations

Newspapers

Individuals

  • Tom Steyer, billionaire, hedge fund manager, philanthropist, environmentalist, liberal activist, and fundraiser

U.S. Representatives

State officials

Local officials

Organizations

Fundraising

Campaign finance reports as of October 19, 2018
CandidateTotal receiptsTotal disbursementsCash on hand
Dianne Feinstein (D)$21,100,086.64$17,896,407.61$4,069,222.18
Kevin de León (D)$1,572,160.70$1,263,113.97$309,045.58
Source: Federal Election Commission

Predictions

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.

SourceRankingAs of
The Cook Political ReportSolid D (Feinstein)September 28, 2018
Inside ElectionsSolid D (Feinstein)November 14, 2017
Sabato's Crystal BallSafe D (Feinstein)November 15, 2017
Daily KosSafe D (Feinstein)April 9, 2018
Fox NewsLikely D (Feinstein)July 9, 2018
CNNSolid D (Feinstein)July 12, 2018
RealClearPoliticsSafe D (Feinstein)June 27, 2018
FiveThirtyEightSolid D (Feinstein)October 20, 2018

Polling

Poll sourceDate(s) administeredSample sizeMargin of errorDianne Feinstein (D)Kevin de León (D)NoneOtherUndecided
Change ResearchNovember 2–4, 20181,108–42%32%–––
Research Co.November 1–3, 2018450± 4.6%47%28%––25%
SurveyUSANovember 1–2, 2018806± 4.7%50%36%––14%
Probolsky ResearchOctober 25–30, 2018900± 3.3%41%35%––24%
UC BerkeleyOctober 19–25, 20181,339± 4.0%45%36%––19%
YouGovOctober 10–24, 20182,178± 3.1%36%29%19%–16%
Public Policy Institute of CaliforniaOctober 12–21, 2018989± 4.2%43%27%23%–8%
Emerson CollegeOctober 17–19, 2018671± 4.1%41%23%––37%
SurveyUSAOctober 12–14, 2018762± 4.9%40%26%––35%
USC Dornsife/Los Angeles TimesSeptember 17 – October 14, 2018794 LV± 4.0%44%31%––25%
980 RV± 4.0%41%30%––29%
1st Tuesday CampaignsOctober 1–3, 20181,038± 3.0%43%30%––27%
Vox Populi PollingSeptember 16–18, 2018500± 4.4%55%45%–––
Public Policy Institute of CaliforniaSeptember 9–18, 2018964± 4.8%40%29%23%–8%
IpsosSeptember 5–14, 20181,021± 4.0%44%24%–17%15%
Probolsky Research (R)August 29 – September 2, 2018900± 5.8%37%29%––34%
Public Policy Institute of CaliforniaJuly 8–17, 20181,020± 4.3%46%24%20%–9%
SurveyUSAJune 26–27, 2018559± 5.9%46%24%––31%
USC Dornsife/Los Angeles TimesJune 6–17, 2018767± 4.0%36%18%––46%
Probolsky Research (R)April 16–18, 2018900± 3.3%38%27%––35%
USC Dornsife/Los Angeles TimesOctober 27 – November 6, 20171,296± 4.0%58%31%31%10%–
Sextant Strategies & ResearchSeptember 20171,554–36%17%28%–19%

with Feinstein, de León, and Tom Steyer

Poll sourceDate(s) administeredSample sizeMargin of errorKevin de León (D)Dianne Feinstein (D)Tom Steyer (D)Not votingOther
USC Dornsife/Los Angeles TimesOctober 27 – November 6, 2017949± 4.0%24%50%17%31%9%

with Feinstein, de León, and John Cox

Poll sourceDate(s) administeredSample sizeMargin of errorJohn Cox (R)Kevin de León (D)Dianne Feinstein (D)Undecided
Sextant Strategies & ResearchSeptember 20171,197± 3.4%30%15%38%17%

Results

2018 United States Senate election in California
PartyCandidateVotes%
DemocraticDianne Feinstein (incumbent)6,019,42254.16%
DemocraticKevin de León5,093,94245.84%
Total votes11,113,364100.00%
Democratic hold

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.

By county

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

CountyFeinstein #Feinstein%de León #de León%Margin #Margin%Total
Alameda318,37758.38226,95041.6291,42716.77545,327
Alpine26748.8128051.19-13-2.38547
Amador5,83541.448,24458.56-2,409-17.1114,079
Butte32,41842.9243,10857.08-10,690-14.1575,526
Calaveras7,03140.4410,35759.56-3,326-19.1317,388
Colusa1,64335.093,03964.91-1,396-29.824,682
Contra Costa222,34958.34158,74841.6663,60116.69381,097
Del Norte2,59037.844,25462.16-1,664-24.316,844
El Dorado33,77246.5438,79153.46-5,019-6.9272,563
Fresno103,49147.68113,55752.32-10,066-4.64217,048
Glenn2,34134.794,38865.21-2,047-30.426,729
Humboldt21,33644.7726,31955.23-4,983-10.4647,655
Imperial13,12143.3517,15056.65-4,029-13.3130,271
Inyo2,34439.893,53260.11-1,188-20.225,876
Kern66,62839.9999,98160.01-33,353-20.02166,609
Kings9,59937.8715,74862.13-6,149-24.2625,347
Lake8,14244.1110,31755.89-2,175-11.7818,459
Lassen2,03029.774,78870.23-2,758-40.456,818
Los Angeles1,565,16757.731,146,04442.27419,12315.462,711,211
Madera13,28441.1119,03258.89-5,748-17.7932,316
Marin80,31965.3242,63834.6837,68130.65122,957
Mariposa2,74941.103,93958.90-1,190-17.796,688
Mendocino15,11349.3215,52950.68-416-1.3630,642
Merced23,65945.8127,98554.19-4,326-8.3851,644
Modoc75128.691,86771.31-1,116-42.632,618
Mono2,00147.672,19752.33-196-4.674,198
Monterey56,32052.6950,56247.315,7585.39106,882
Napa27,90454.5123,29045.494,6149.0151,194
Nevada22,19848.1423,91151.86-1,713-3.7246,109
Orange501,67854.38420,81445.6280,8648.77922,492
Placer66,57846.4676,73353.54-10,155-7.09143,311
Plumas2,81538.874,42861.13-1,613-22.277,243
Riverside269,56749.19278,40950.81-8,842-1.61547,976
Sacramento241,57153.03213,94946.9727,6226.06455,520
San Benito8,60747.889,37152.12-764-4.2517,978
San Bernardino233,10349.97233,36050.03-257-0.06466,463
San Diego526,62852.92468,56447.0858,0645.83995,192
San Francisco226,16764.23125,95435.77100,21328.46352,121
San Joaquin79,08846.1392,35153.87-13,263-7.74171,439
San Luis Obispo53,24249.6354,02750.37-785-0.73107,269
San Mateo168,67962.9899,13637.0269,54325.97267,815
Santa Barbara75,27455.1561,21744.8514,05710.30136,491
Santa Clara339,86659.78228,64240.22111,22419.56568,508
Santa Cruz64,17857.5147,41642.4916,76215.02111,594
Shasta19,39734.8736,22765.13-16,830-30.2655,624
Sierra50638.5180861.49-302-22.981,314
Siskiyou5,77239.268,93060.74-3,158-21.4814,702
Solano70,17452.8962,50647.117,6685.78132,680
Sonoma108,47256.0085,22044.0023,25212.00193,692
Stanislaus58,37542.8977,72457.11-19,349-14.22136,099
Sutter10,50142.5714,16657.43-3,665-14.8624,667
Tehama5,43532.5711,25367.43-5,818-34.8616,688
Trinity1,74638.092,83861.91-1,092-23.824,584
Tulare33,00539.8849,76560.12-16,760-20.2582,770
Tuolumne7,78340.8511,27159.15-3,488-18.3119,054
Ventura137,14151.32130,10148.687,0402.63267,242
Yolo35,07151.8632,55148.142,5203.7367,622
Yuba6,22439.179,66660.83-3,442-21.6615,890
Totals6,019,42254.165,093,94245.84925,4808.3311,113,364

By congressional district

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

DistrictFeinsteinDe LeónRepresentative
1st40%60%Doug LaMalfa
2nd57%43%Jared Huffman
3rd47%53%John Garamendi
4th45%55%Tom McClintock
5th56%44%Mike Thompson
6th57%43%Doris Matsui
7th51%49%Ami Bera
8th46%54%Paul Cook
9th49%51%Jerry McNerney
10th43%57%Josh Harder
11th60%40%Mark DeSaulnier
12th64%36%Nancy Pelosi
13th59%41%Barbara Lee
14th64%36%Jackie Speier
15th57%43%Eric Swalwell
16th48%52%Jim Costa
17th60%40%Ro Khanna
18th61%39%Anna Eshoo
19th58%42%Zoe Lofgren
20th54%46%Jimmy Panetta
21st43%57%TJ Cox
22nd44%56%Devin Nunes
23rd40%60%Kevin McCarthy
24th53%47%Salud Carbajal
25th49.7%50.3%Katie Hill
26th52%48%Julia Brownley
27th60%40%Judy Chu
28th58%42%Adam Schiff
29th55%45%Tony Cárdenas
30th62%38%Brad Sherman
31st51%49%Pete Aguilar
32nd53%47%Grace Napolitano
33rd62%38%Ted Lieu
34th52%48%Jimmy Gomez
35th52%48%Norma Torres
36th48%52%Raul Ruiz
37th64%36%Karen Bass
38th54%46%Linda Sánchez
39th56%44%Gil Cisneros
40th51%49%Lucille Roybal-Allard
41st52%48%Mark Takano
42nd48%52%Ken Calvert
43rd62%38%Maxine Waters
44th57%43%Nanette Barragán
45th54%46%Katie Porter
46th53%47%Lou Correa
47th55%45%Alan Lowenthal
48th55%45%Harley Rouda
49th53%47%Mike Levin
50th48%52%Duncan Hunter
51st48%52%Juan Vargas
52nd56%44%Scott Peters
53rd55%45%Susan Davis

External links

Official campaign websites