Kelly: 50-60% 60-70% 70-80%
McSally: 50-60% 60-70% 70-80%
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 through the end of the term expiring in January 2023. 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, which would trigger a special election. 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 solidly 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 0.3%, 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.
Incumbent McSally faced one challenger: Daniel McCarthy, a skincare company executive. Upon his respective announcements, McCarthy's independent wealth was expected to set up a bruising and expensive primary campaign, however, McSally won the primary in a landslide.
|Republican||Martha McSally (incumbent)||551,119||75.2%|
|Republican||Sean Lyons (write-in)||210||nil|
|Democratic||Bo Garcia (write-in)||451||0.1%|
Neither one of the write-in candidates received enough votes to secure the Libertarian nomination in the general election.
|Libertarian||Barry Hess (write-in)||329||76.5%|
|Libertarian||Alan White (write-in)||101||23.5%|
|The Cook Political Report||Lean D (flip)||October 29, 2020|
|Inside Elections||Tilt D (flip)||October 28, 2020|
|Sabato's Crystal Ball||Lean D (flip)||November 2, 2020|
|Daily Kos||Lean D (flip)||October 30, 2020|
|Politico||Lean D (flip)||November 2, 2020|
|RCP||Tossup||October 23, 2020|
|DDHQ||Likely D (flip)||November 3, 2020|
|538||Likely D (flip)||November 2, 2020|
|Economist||Lean D (flip)||November 2, 2020|
|Mark Kelly vs. Martha McSally|
|Source of poll aggregation||Dates administered||Dates updated||Mark Kelly||Martha McSally||Margin|
|270 to Win||November 2, 2020||November 3, 2020||49.8%||44.8%||Kelly +5.0|
|Real Clear Politics||November 1, 2020||November 3, 2020||50.5%||44.8%||Kelly +5.7|
|Republican||Martha McSally (incumbent)||1,637,661||48.8%||-4.9%|
|Write-in||1,189||< 0.1%||< 0.1%|
|Democratic gain from Republican|
The endorsees include Senate hopeful Mark Kelly, a Democrat running to unseat Sen. Martha McSally (R) in Arizona,
Official campaign websites