2020 United States Senate special election in Arizona

The 2020 United States Senate special election in Arizona was held on November 3, 2020, following the death in office of incumbent Republican U.S. Senator John McCain on August 25, 2018. Governor Doug Ducey was required by Arizona law to appoint a Republican to fill the vacant seat until a special election winner could be sworn in. On September 5, 2018, Ducey appointed former U.S. Senator Jon Kyl to fill McCain's seat. However, Kyl announced he would resign on December 31, 2018.

On December 18, 2018, Ducey announced that outgoing U.S. Representative Martha McSally would be appointed to fill the seat following Kyl's resignation. McSally was sworn in as the state's junior U.S. Senator on January 3, 2019, less than two months after she was defeated by Democrat Kyrsten Sinema for Arizona's Class 1 U.S. Senate seat. McSally ran to complete the term, defeating skincare executive Daniel McCarthy in the Republican primary. She faced former astronaut Mark Kelly, who ran uncontested in the Democratic primary. Primary elections took place on August 4, 2020.

Once a reliably Republican state, Arizona trended more purple in the late 2010s. Kelly significantly outraised McSally and led by about 5% in the average poll leading up to Election Day.

Kelly defeated McSally by a margin of 2.4% on election night, thereby flipping the seat Democratic. As a result, he outperformed Joe Biden in the concurrent presidential election, who defeated President Donald Trump by a margin of 0.3% in the state, but underperformed his polling average. Kelly became the first Democrat to win the Class 3 Senate seat since Carl Hayden won his last term in 1962. This also marked the first time since the 82nd Congress preceding the 1952 election that Democrats held both Senate seats in Arizona.

Kelly was sworn in on December 2, 2020.

Appointees

 * Jon Kyl, former U.S. senator, former U.S. Representative for Arizona's 4th congressional district and former Senate Minority Whip, resigned December 31, 2018
 * Martha McSally, former U.S. representative for Arizona's 2nd congressional district, 2018 Republican nominee for U.S. Senate, assumed office January 3, 2019

Potential candidates not appointed

 * Kirk Adams, incumbent chief of staff to incumbent governor of Arizona Doug Ducey and former speaker of the Arizona House of Representatives
 * Barbara Barrett, Secretary of the Air Force and former United States Ambassador to Finland
 * Jan Brewer, former governor of Arizona and former secretary of state of Arizona
 * Paul Gosar, incumbent U.S. representative for Arizona's 4th congressional district
 * Eileen Klein, former treasurer of Arizona and former chief of staff to former governor of Arizona Jan Brewer
 * Cindy McCain, widow of former U.S. senator John McCain
 * Meghan McCain, daughter of former U.S. senator John McCain
 * Mick McGuire, incumbent adjutant general of the Arizona National Guard
 * Karrin Taylor Robson, businesswoman and incumbent member of the Arizona Board of Regents
 * Matt Salmon, former U.S. representative, 2002 gubernatorial nominee and former chairperson of the Arizona Republican Party
 * David Schweikert, incumbent U.S. representative for Arizona's 6th congressional district
 * John Shadegg, former U.S. representative for Arizona's 3rd congressional district
 * Kelli Ward, former candidate for U.S. Senate in 2016 and 2018
 * Grant Woods, former Republican Arizona Attorney General and former congressional chief of staff to former U.S. senator John McCain

Republican primary
Incumbent McSally faced one challenger: Daniel McCarthy, a skincare company executive. McCarthy's independent wealth was expected to set up a bruising and expensive primary campaign; however, McSally won the primary in a landslide.

Nominee

 * Martha McSally, incumbent U.S. senator and former U.S. Representative for Arizona's 2nd congressional district

Eliminated in primary

 * Sean Lyons (as a write-in candidate)
 * Daniel McCarthy, skincare company executive

Withdrawn

 * Craig Brittain, former revenge porn site operator
 * PT Burton
 * Mark Cavener
 * Floyd Getchell
 * Ann Griffin, former teacher
 * Josue Larose, 2016 Republican presidential candidate and 2012 Republican candidate for Louisiana's 2nd congressional district

Declined

 * Kirk Adams, incumbent chief of staff to incumbent governor of Arizona Doug Ducey and former Speaker of the Arizona House of Representatives
 * Joe Arpaio, former Sheriff of Maricopa County and candidate for U.S. Senate in 2018 (running for Maricopa County Sheriff)
 * Doug Ducey, governor of Arizona
 * Paul Gosar, U.S. representative for Arizona's 4th congressional district (ran for re-election)
 * Jon Kyl, former U.S. senator, former U.S. Representative for Arizona's 4th congressional district and former Senate Minority Whip
 * Blake Masters, president of the Thiel Foundation
 * Curt Schilling, former Major League Baseball player and Blaze Media commentator
 * Fife Symington, former governor of Arizona

Nominee

 * Mark Kelly, retired astronaut, engineer, retired U.S. Navy captain, husband of former U.S. Representative Gabby Giffords

Eliminated in primary

 * Bo "Heir Archy" Garcia (as a write-in candidate)

Withdrew

 * Mohammad Arif, businessman and perennial candidate (write-in) (switched to Democratic general election write-in candidacy)
 * Sheila Bilyeu, Democratic candidate for the 2020 United States Senate election in Oklahoma
 * Juan Angel Vasquez

Declined

 * Ruben Gallego, incumbent U.S. representative for Arizona's 7th congressional district (running for re-election) (endorsed Mark Kelly)
 * Katie Hobbs, Secretary of State of Arizona
 * Grant Woods, former Republican Arizona Attorney General and former congressional chief of staff to former U.S. senator John McCain

Libertarian primary
Neither one of the write-in candidates received enough votes to secure the Libertarian nomination in the general election.

Eliminated in primary

 * Barry Hess, write-in Libertarian candidate in the 2018 United States Senate election in Arizona and Libertarian nominee in the 2014 Arizona gubernatorial election
 * Alan White

Declared

 * Republican
 * Edward Davida
 * John Schiess
 * Debbie Simmons
 * Patrick "Pat" Thomas


 * Democratic
 * Mohammed "Mike Obama" Arif
 * Adam Chilton
 * Perry Kapadia
 * Buzz Stewart


 * Other
 * Christopher Beckett, veteran (Independent)
 * William "Will" Decker (Independent)
 * Matthew "Doc" Dorchester (Libertarian)
 * Nicholas N. Glenn, Navy veteran and aerospace engineer (Independent Republican)
 * Mathew Haupt (Independent)
 * Benjamin Rodriguez (Independent)
 * Joshua Rodriguez (Unity)
 * Frank Saenz (Independent)
 * Jim Stevens (Independent)

Withdrawn

 * Robert Kay (Independent)

Debates

 * Complete video of debate, October 6, 2020

Aggregate polls

 * with Daniel McCarthy and Mark Kelly


 * with Ruben Gallego


 * on whether McSally deserves to be re-elected


 * with generic Republican and generic Democrat

Results

 * Counties that flipped from Republican to Democratic
 * Maricopa (largest municipality: Phoenix)