# 2020 United States Senate election in Maine

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The 2020 United States Senate election in Maine was held on November 3, 2020, to elect a member of the United States Senate to represent the State of Maine, concurrently with the 2020 U.S. presidential election, as well as other elections to the United States Senate, elections to the United States House of Representatives, and various state and local elections. This was Maine's first election for its Class 2 seat to use its ranked choice voting system. Because the first round of the general election saw a majority, the instant runoff tabulation of more than 800,000 ballots was not carried out.
Republican Senator Susan Collins was challenged by Democratic nominee Sara Gideon, the speaker of the Maine House of Representatives, as well as independent candidates Lisa Savage and Max Linn. Collins was considered one of the most vulnerable Republican senators due to her decreased polling numbers and perceived harm to her reputation, but she was re-elected by an unexpectedly large 8.6% margin, with 51% of the vote to Gideon's 42.4%. Despite this, her 51% share of the vote was her worst performance since her first election in 1996 and was a 17-point drop from 2014. Maine was the only state to elect a senator of a different party than the winner of its presidential contest in the November 3 election, with Collins outperforming President Donald Trump, who lost the state to Democratic nominee Joe Biden by 9.1%.

## Background

Republican senator Susan Collins, widely considered one of the two least conservative Republican U.S. senators (the other being Lisa Murkowski), ran for a fifth term. Collins had won each election to this seat by a greater victory margin than the one before it. Observers did not anticipate this election to continue that trend.
Collins was criticized for her decision to vote to confirm Brett Kavanaugh to the United States Supreme Court despite his anti-abortion stances (Collins describes herself as pro-choice) and allegations of sexual misconduct and abuse against him, though she gave a highly publicized speech on the Senate floor explaining her reasoning. She also faced criticism for her stance on the impeachment of President Donald Trump. Collins voted in favor of allowing witness testimony in the Senate trial, and was the first Republican to do so, and she voted to acquit Trump on both charges of abuse of power and obstruction of Congress. She said she voted to acquit because "impeachment of a president should be reserved for conduct that poses such a serious threat to our governmental institutions as to warrant the extreme step of immediate removal from office." She initially claimed that Trump "learned a pretty big lesson" from the impeachment, but later said that she thought he had not learned from it after all. She has also been criticized for running for third, fourth, and fifth Senate terms despite vowing to serve no more than two terms during her 1996 campaign, though she has explained this as a product of having learned the value of seniority in the Senate. The emphasis on seniority became a key theme of her campaign. Collins's campaign emphasized her efficiency as a legislator, her efforts to pass the Paycheck Protection Program and other aid for small businesses, and her growing seniority and influence in the Senate, in particular her potential chairwomanship of the Appropriations Committee.
The Democratic nominee, Speaker of the Maine House of Representatives Sara Gideon, supports criminal justice reforms, expansion of the Affordable Care Act, rejoining the Paris Climate Accord, and imposing universal background checks on gun sales to combat gun violence. In 2019, Gideon faced an election ethics complaint for accepting reimbursements for her political donations from her own PAC. Gideon apologized for the violation, reimbursed the federal government a total of $3,250, and closed the PAC. Gideon was also criticized for keeping the Maine House of Representatives adjourned for most of the year (neighboring New Hampshire had reconvened its sizably larger legislature by late spring) and for allegedly turning a blind eye to a legislative colleague accused of molesting underage girls until she was forced to acknowledge the scandal.
Lisa Savage, a longtime antiwar activist and schoolteacher from Solon, initially sought the Maine Green Independent Party nomination, but in late February, she announced her intention to instead qualify for the ballot as an independent due to Maine's restrictive ballot access measures. In April, Savage turned in more than 5,500 signatures to the Secretary of State's office and thus qualified for the general election ballot.
Max Linn, a financial planner and conservative activist from Bar Harbor, was a Trump supporter and former candidate of the Republican and Reform parties. In July 2020, he qualified for the ballot as an independent. Former Republican state senator Mary Small challenged the signatures on his petition, but the secretary of state found that he had enough and he was placed on the ballot. Later that month, he announced his intention to drop out of the race to support Collins. But days later, he decided not to drop out unless Collins agreed to a list of policies, which she did not.
Party primaries were initially scheduled to take place on June 9, but due to the COVID-19 pandemic and its impact on the state, Governor Janet Mills rescheduled them for July 14. Mills's executive order also expanded voters' ability to request absentee ballots, which could then be done up to and on election day. The primaries were conducted with ranked choice voting. Parties qualified to participate in the 2020 primary election were the Democratic Party, the Republican Party, and the Maine Green Independent Party.

## Republican primary
### Candidates
#### Nominee

* Susan Collins, incumbent U.S. senator

#### Eliminated in primary

* Amy Colter, law office manager (write-in candidate)

#### Withdrawn

* Derek Levasseur, police officer

#### Declined

* Paul LePage, former governor of Maine (endorsed Collins)
* Max Linn, financial planner, Reform nominee for governor of Florida in 2006, Democratic candidate for Florida's 10th congressional district in 2008 and disqualified candidate for U.S. Senate in 2018 (qualified for the general election as Independent)
* Bruce Poliquin, former U.S. representative for Maine's 2nd congressional district and former Treasurer of Maine

### Polling

| Poll source | Date(s) administered | Sample size | Margin of error | Susan Collins | Derek Levasseur | Undecided |
| Public Policy Polling (D) | October 11–13, 2019 | 271 (LV) | ± 6% | 55% | 10% | 34% |
with Susan Collins and Paul LePage
| Poll source | Date(s) administered | Sample size | Margin of error | Susan Collins | Paul LePage | Undecided |
| Public Policy Polling (D) | October 11–13, 2019 | 271 (LV) | ± 6% | 29% | 63% | 8% |
with Susan Collins and Shawn Moody
| Poll source | Date(s) administered | Sample size | Margin of error | Susan Collins | Shawn Moody | Undecided |
| Public Policy Polling (D) | October 11–13, 2019 | 271 (LV) | ± 6% | 36% | 45% | 18% |
with Susan Collins and generic Republican if Collins supported impeaching Trump
| Poll source | Date(s) administered | Sample size | Margin of error | Susan Collins | Generic Republican | Undecided |
| Public Policy Polling (D) | October 11–13, 2019 | 271 (LV) | ± 6% | 35% | 55% | 10 |
with Susan Collins and Derek Levasseur if Collins supported impeaching Trump
| Poll source | Date(s) administered | Sample size | Margin of error | Susan Collins | Derek Levasseur | Undecided |
| Public Policy Polling (D) | October 11–13, 2019 | 271 (LV) | ± 6% | 37% | 24% | 39% |
with Susan Collins and generic Republican
| Poll source | Date(s) administered | Sample size | Margin of error | Susan Collins | Generic Republican | Undecided |
| Public Policy Polling (D) | October 11–13, 2019 | 271 (LV) | ± 6% | 53% | 38% | 9% |

### Results

Republican primary results :
| Party | Party | Candidate | Votes | % |
| | Republican | Susan Collins (incumbent) | 87,375 | 98.79% |
| | Republican | Amy Colter (write-in) | 1,073 | 1.21% |
| Total votes | Total votes | Total votes | 88,448 | 100.0% |

## Democratic primary

On April 20, 2019, attorney and activist Bre Kidman became the first person to announce their candidacy for the Democratic nomination. If elected, they would have been the first ever U.S. Senator who identifies as non-binary. On June 13, 2019, former Maine gubernatorial candidate Betsy Sweet declared her candidacy. Eleven days later, Maine House Speaker Sara Gideon announced her candidacy, receiving widespread media coverage. General Jon Treacy had previously announced his candidacy before withdrawing. Former Google executive and political aide Ross LaJeunesse, who would have been the first openly gay man elected to the Senate, announced his candidacy in November 2019. He received the endorsement of the national political group The Victory Fund in January 2020. LaJeunesse eventually withdrew from the race in March 2020, citing the inability to continue his strategy of campaigning in person due to the COVID-19 pandemic, and endorsed Gideon. Two debates were held with all three candidates, while one hosted by WCSH was attended only by Sweet and Kidman.

### Candidates
#### Nominee

* Sara Gideon, Speaker of the Maine House of Representatives

#### Eliminated in primary

* Bre Kidman, attorney, activist, and artist
* Betsy Sweet, activist, former director of the Maine Women's Lobby, and candidate for Governor of Maine in 2018

#### Withdrawn

* Michael Bunker, travel agent
* Christine Gates
* Ross LaJeunesse, former Head of International Relations at Google, former aide to George J. Mitchell, Ted Kennedy, Steve Westly and Arnold Schwarzenegger (endorsed Gideon)
* Cathleen London, physician and member of the Maine Democratic Party State Committee
* Jon Treacy, retired U.S. Air Force major general

#### Declined

* Shenna Bellows, state senator and nominee for U.S. Senate in 2014
* Seth Berry, state representative (endorsed Gideon)
* Emily Cain, executive director of EMILY's List, nominee for Maine's 2nd congressional district in 2014 and 2016, former state senator, and former state representative
* Adam Cote, candidate for Maine's 1st congressional district in 2008 and candidate for governor of Maine in 2018
* Matthew Dunlap, Maine Secretary of State and candidate for U.S. Senate in 2012
* Jared Golden, incumbent U.S. representative for Maine's 2nd congressional district and former state representative
* James Howaniec, former mayor of Lewiston
* Stephen King, author (endorsed Gideon)
* Daniel Kleban, businessman
* Janet Mills, governor of Maine and former attorney general of Maine
* Chellie Pingree, incumbent U.S. representative for Maine's 1st congressional district and nominee for the U.S. Senate in 2002
* Hannah Pingree, former Speaker of the Maine House of Representatives (endorsed Gideon)
* Susan Rice, former United States National Security Advisor and former United States Ambassador to the United Nations
* Cecile Richards, former president of Planned Parenthood
* Zak Ringelstein, schoolteacher and nominee for U.S. Senate in 2018 (endorsed Sweet)
* Rosa Scarcelli, businesswoman and candidate for governor of Maine in 2010
* Ethan Strimling, former mayor of Portland and candidate for Maine's 1st congressional district in 2008

### Polling

| Poll source | Date(s) administered | Sample size | Margin of error | Sara Gideon | Betsy Sweet | Other / Undecided |
| Victory Geek (D) | May 13–18, 2020 | – (LV) | – | 67% | 17% | 17% |
| Colby College/SocialSphere | February 10–13, 2020 | 383 (LV) | – | 60% | 8% | 33% |

### Results

Democratic primary results :
| Party | Party | Candidate | Votes | % |
| | Democratic | Sara Gideon | 116,264 | 71.47% |
| | Democratic | Betsy Sweet | 37,327 | 22.94% |
| | Democratic | Bre Kidman | 9,090 | 5.59% |
| Total votes | Total votes | Total votes | 162,681 | 100.0% |

## Other candidates
### Green Independent Party

Two candidates declared their intentions to run for the Maine Green Independent Party's nomination, but one withdrew and the other left the party to become an independent. Lisa Savage left the party because of Maine's ballot access requirements; Savage needed 2,000 registered party members to sign a nomination petition to appear on the ballot as the Green Party candidate but could only gather them from January 1 until the March 15 deadline. The Green Party had roughly 41,000 members statewide, which was significantly fewer than the Democratic and Republican parties but nonetheless required the same number of signatures. No alternative party candidate for statewide office had been able to meet this requirement since Pat LaMarche did so in 2006 for governor. Instead, Savage sought to appear as an independent candidate, which required 4,000 signatures, but they may be from any registered voter, not just party members, and they could have been gathered until the June deadline.

#### Withdrawn

* David Gibson, solar design specialist (endorsed Savage)
* Lisa Savage, school teacher (switched to independent)

### Write-in candidates

* Tiffany Bond, lawyer and candidate for Maine's 2nd congressional district in 2018
* Ian Kenton Engelman
* Douglas E. Fogg

### Independents

Eight Independents declared their candidacy for Senate in 2020, including one affiliated with the Libertarian Party of Maine, which lost ballot access after the 2018 elections. Two qualified for positions on the November ballot.

#### Declared

* Max Linn, perennial candidate, financial planner, and disqualified Republican candidate for the 2018 United States Senate election in Maine
* Lisa Savage, peace activist and schoolteacher (switched from Green Independent candidacy)

#### Withdrawn

* Joshua Arnone, accounting clerk affiliated with the Libertarian Party of Maine
* Steven Golieb, Millinocket town councilor
* Leigh Hawes, truck driver
* Danielle VanHelsing, LGBTQ rights activist
* Linda Wooten, vocational educator and conservative activist

## General election
### Predictions

| Source | Ranking | As of |
| The Cook Political Report | Tossup | October 29, 2020 |
| Inside Elections | Tilt D (flip) | October 28, 2020 |
| Sabato's Crystal Ball | Lean D (flip) | November 2, 2020 |
| Daily Kos | Tossup | October 30, 2020 |
| Politico | Tossup | November 2, 2020 |
| RCP | Tossup | October 23, 2020 |
| DDHQ | Lean D (flip) | November 3, 2020 |
| 538 | Tossup | November 2, 2020 |
| Economist | Lean D (flip) | November 2, 2020 |

### Debates

The four candidates participated in two in-person debates on September 11 and September 29, both held without an audience. Collins at one point proposed holding 16 debates, one for every county in Maine, but such a schedule was not agreed upon.
2020 United States Senate election in Maine debates :
| N° | Date | Moderator | Participants | Participants | Participants | Participants |
| Key: P Participant. NI Not invited. | Key: P Participant. NI Not invited. | Key: P Participant. NI Not invited. | Republican | Democratic | Independent | Independent |
| Key: P Participant. NI Not invited. | Key: P Participant. NI Not invited. | Key: P Participant. NI Not invited. | United States Senator Susan Collins | Maine House Speaker Sara Gideon | Financial planner Max Linn | Public schoolteacher Lisa Savage |
| 1 | Friday, September 11, 2020 | Pat Callaghan Rachel Ohm Michael Shepherd | P | P | P | P |
| 2 | Tuesday, September 29, 2020 | Kelly O'Mara Jason Parent | P | P | P | P |
| 3 | Thursday, October 15, 2020 | Jennifer Rooks Steve Mistler Mal Leary | P | P | P | P |
| 4 | Thursday, October 22, 2020 | Pat Callaghan | P | P | P | P |
| 5 | Wednesday, October 28, 2020 | Steve Bottari | P | P | NI | NI |

### Endorsements

U.S. presidents
* George W. Bush, 43rd president of the United States (2001–2009), 46th governor of Texas (1995–2000)
* Donald Trump, 45th president of the United States (2017–2021)
U.S. senators
* William Cohen, former U.S. senator from Maine (1979–1997), former United States Secretary of Defense (1997–2001)
* Lindsey Graham, U.S. senator from South Carolina (2003–present)
* Joe Lieberman, former U.S. senator from Connecticut (1989–2013), 2000 Democratic nominee for Vice President of the United States (former Democrat, Independent since 2006)
* Joe Manchin, U.S. senator from West Virginia (2010–present), former governor of West Virginia (2005–2010) (Democrat)
U.S. governors
* Charlie Baker, 72nd governor of Massachusetts (2015–2023)
* Larry Hogan, 62nd governor of Maryland (2015–2023)
* Paul LePage, 74th governor of Maine (2011–2019), mayor of Waterville (2003–2011)
Individuals
* Laura Bush, former First Lady of the United States (2001–2009), former First Lady of Texas (1995–2000)
Organizations
* Maggie's List
* Maine Fraternal Order of Police
U.S. presidents
* Barack Obama, 44th president of the United States
U.S. vice presidents
* Joe Biden, 47th vice president of the United States, 2020 Democratic nominee for president
U.S. senators
* Catherine Cortez Masto, U.S. senator from Nevada (2017–present)
* Tammy Duckworth, U.S. senator from Illinois (2017–present)
* Kirsten Gillibrand, U.S. senator from New York (2009–present); former 2020 presidential candidate
* Kamala Harris, U.S. senator from California (2017–2021); 2020 Democratic vice presidential nominee
* Chris Murphy, U.S. senator from Connecticut (2013–present)
* Elizabeth Warren, U.S. senator from Massachusetts (2013–present), former 2020 presidential candidate
Members of U.S. Congress
* Chellie Pingree, US Representative for Maine's 1st congressional district (2009–present)
State executive officials
* Janet Mills, Governor of Maine (2019–present)
State legislators
* Stacey Abrams, former Democratic leader of the Georgia House of Representatives, 2018 nominee for governor of Georgia
Individuals
* Stephen King, author
* Ross LaJeunesse, former aide to George J. Mitchell, Ted Kennedy, Steve Westly and Arnold Schwarzenegger
Organizations
* Asian American Action Fund
* Bend the Arc: Jewish Action
* CAPA21
* Council for a Livable World
* Democratic Majority for Israel
* Emerge America
* Everytown for Gun Safety
* Feminist Majority PAC
* J Street PAC
* Joint Action Committee for Political Affairs
* NARAL
* National Organization for Women
* Natural Resources Defense Council Action Fund
* Planned Parenthood
* Population Connection
* Sierra Club
* Voter Protection Project
* Women's Political Committee
Unions
* Carpenters Local 349
* Carpenters Local 352
* Heat and Frost Insulators Local 6
* International Union of Operating Engineers
* Maine State Association of Letter Carriers
* United Food and Commercial Workers Local 791
* United Food and Commercial Workers Local 1445
* Jared Golden, U.S. representative (ME-02) (Democratic)

### Polling
#### Aggregate polls

Sara Gideon vs. Susan Collins :
| Source of poll aggregation | Dates administered | Dates updated | Sara Gideon | Susan Collins | Other/undecided | Margin |
| 270 to Win | October 6 – November 1, 2020 | November 3, 2020 | 46.4% | 42.6% | 11.0% | Gideon +3.8 |
| Real Clear Politics | September 10–23, 2020 | September 25, 2020 | 48.5% | 42.0% | 9.5% | Gideon +6.5 |
| Poll source | Date(s) administered | Sample size | Margin of error | Susan Collins (R) | Sara Gideon (D) | Lisa Savage (I) | Other / Undecided |
| Change Research | October 29 – November 2, 2020 | 1,024 (LV) | ± 3.5% | 42% | 46% | 7% | 5% |
| Change Research | October 29 – November 2, 2020 | 1,024 (LV) | ± 3.5% | 46% | 54% | – | – |
| Emerson College | October 29–31, 2020 | 611 (LV) | ± 3.9% | 46% | 48% | 5% | 5% |
| Emerson College | October 29–31, 2020 | 611 (LV) | ± 3.9% | 47% | 51% | – | 5% |
| SurveyUSA | October 23–27, 2020 | 1007 (LV) | ± 3.7% | 45% | 46% | 4% | 5% |
| SurveyUSA | October 23–27, 2020 | 1007 (LV) | ± 3.7% | 49% | 51% | – | – |
| Colby College | October 21–25, 2020 | 879 (LV) | ± 3.3% | 43% | 47% | 5% | 5% |
| Colby College | October 21–25, 2020 | 879 (LV) | ± 3.3% | 44% | 49% | – | 7% |
| Pan Atlantic Research | October 2–6, 2020 | 600 (LV) | ± 4.5% | 40% | 47% | 5% | 8% |
| Pan Atlantic Research | October 2–6, 2020 | 600 (LV) | ± 4.5% | 41% | 49% | 1% | 9% |
| Critical Insights | September 25 – October 4, 2020 | 466 (LV) | ± 4.4% | 43% | 44% | 3% | 11% |
| Critical Insights | September 25 – October 4, 2020 | 466 (LV) | ± 4.4% | 43% | 46% | 1% | 10% |
| Data for Progress (D) | September 23–28, 2020 | 718 (LV) | ± 3.7% | 41% | 46% | 3% | 11% |
| Data for Progress (D) | September 23–28, 2020 | 718 (LV) | ± 3.7% | 42% | 50% | – | 8% |
| Colby College | September 17–23, 2020 | 847 (LV) | ± 3.4% | 41% | 45% | 3% | 11% |
| Colby College | September 17–23, 2020 | 847 (LV) | ± 3.4% | 43% | 47% | – | 6% |
| Moore Information (R) | September 20–22, 2020 | 600 (LV) | – | 42% | 42% | – | 9% |
| Suffolk University | September 17–20, 2020 | 500 (LV) | ± 4.4% | 41% | 46% | 4% | 7% |
| Suffolk University | September 17–20, 2020 | 500 (LV) | ± 4.4% | 42% | 49% | 1% | 8% |
| Siena College/NYT Upshot | September 11–16, 2020 | 663 (LV) | ± 5.1% | 40% | 44% | 2% | 2% |
| Siena College/NYT Upshot | September 11–16, 2020 | 663 (LV) | ± 5.1% | 44% | 49% | 0% | 7% |
| Quinnipiac University | September 10–14, 2020 | 1,183 (LV) | ± 2.9% | 42% | 54% | – | 4% |
| Citizen Data | September 4–7, 2020 | 600 (LV) | ± 4% | 41% | 49% | 1% | 9% |
| Fabrizio Ward/Hart Research Associates | August 30 – September 5, 2020 | 800 (LV) | ± 3.5% | 43% | 44% | 6% | 8% |
| Fabrizio Ward/Hart Research Associates | August 30 – September 5, 2020 | 800 (LV) | ± 3.5% | 47% | 48% | – | 5% |
| Public Policy Polling | August 13–14, 2020 | 571 (V) | ± 4.1% | 44% | 49% | – | 7% |
| Critical Insights | July 28 – August 9, 2020 | 453 (LV) | ± 4.3% | 38% | 43% | 5% | 15% |
| Critical Insights | July 28 – August 9, 2020 | 499 (RV) | ± 4.3% | 35% | 43% | 5% | 18% |
| Critical Insights | July 28 – August 9, 2020 | 499 (RV) | ± 4.3% | 37% | 44% | 1% | 18% |
| Quinnipiac University | July 30 – August 3, 2020 | 807 (RV) | ± 3.5% | 43% | 47% | – | 10% |
| RMG Research | July 27 – August 2, 2020 | 500 (RV) | ± 4.5% | 41% | 48% | – | 11% |
| Data for Progress | July 24 – August 2, 2020 | 866 (LV) | ± 3.0% | 45% | 48% | – | 7% |
| Colby College/SocialSphere | July 18–24, 2020 | 888 (LV) | ± 3.9% | 39% | 44% | – | 18% |
| Public Policy Polling | July 22–23, 2020 | 561 (V) | ± 3.6% | 42% | 47% | – | 11% |
| Public Policy Polling | July 2–3, 2020 | 1,022 (V) | ± 3.1% | 42% | 46% | – | 11% |
| Moore Information (R) | June 20–24, 2020 | 600 (RV) | ± 4.0% | 45% | 37% | 3% | 1% |
| Victory Geek (D) | May 13–18, 2020 | 512 (LV) | ± 4.3% | 42% | 51% | – | 7% |
| Tarrance Group (R) | April 2020 | – | – | 48% | 47% | – | 5% |
| Public Policy Polling | March 2–3, 2020 | 872 (V) | ± 3.3% | 43% | 47% | – | 10% |
| Colby College/SocialSphere | February 10–13, 2020 | 1,008 (LV) | ± 3.1% | 42% | 43% | – | 14% |
| Fabrizio Ward | July 29–31, 2019 | 600 (LV) | ± 4.0% | 52% | 35% | – | 13% |
| Gravis Marketing | June 24, 2019 | 767 (RV) | ± 3.5% | 44% | 30% | – | 26% |
| Gravis Marketing | June 24, 2019 | 767 (RV) | ± 3.5% | 52% | 36% | – | 12% |
| Pan Atlantic Research | March 4–13, 2019 | 500 (LV) | ± 4.4% | 51% | 29% | – | 20% |
with Betsy Sweet
| Poll source | Date(s) administered | Sample size | Margin of error | Betsy Sweet (D) | Susan Collins (R) | Other / Undecided |
| Victory Geek (D) | May 13–18, 2020 | 512 (LV) | ± 4.3% | 44% | 43% | 10% |
with Susan Rice
| Poll source | Date(s) administered | Sample size | Margin of error | Susan Rice (D) | Susan Collins (R) | Other / Undecided |
| Emerson College | October 27–29, 2018 | 883 (LV) | ± 3.5% | 20% | 44% | 35% |
with generic Democrat
| Poll source | Date(s) administered | Sample size | Margin of error | Generic Democrat | Susan Collins (R) | Other / Undecided |
| Victory Geek (D) | May 13–18, 2020 | 512 (LV) | ± 4.3% | 49% | 39% | 12% |
| Colby College/SocialSphere | Feb 10–13, 2020 | 1,008 (LV) | ± 3.1% | 34% | 40% | 26% |
| Public Policy Polling | October 11–13, 2019 | 939 (V) | ± 3.2% | 44% | 41% | 15% |
| Public Policy Polling | October 1–2, 2018 | – | ± 3.3% | 34% | 42% | – |
| Public Policy Polling (D) | August 28–29, 2017 | 501 (V) | – | 21% | 51% | 27% |
with generic Democrat if Collins supports impeaching Donald Trump
| Poll source | Date(s) administered | Sample size | Margin of error | Generic Democrat | Susan Collins (R) | Other / Undecided |
| Public Policy Polling | October 11–13, 2019 | 939 (V) | ± 3.2% | 38% | 32% | 30% |
with generic Democrat if Collins opposes impeaching Donald Trump
| Poll source | Date(s) administered | Sample size | Margin of error | Generic Democrat | Susan Collins (R) | Other / Undecided |
| Public Policy Polling | October 11–13, 2019 | 939 (V) | ± 3.2% | 47% | 40% | 13% |
with Generic Opponent
| Poll source | Date(s) administered | Sample size | Margin of error | Susan Collins (R) | Generic Opponent | Other / Undecided |
| Fabrizio Ward | July 29–31, 2019 | 600 (LV) | ± 4.0% | 38% | 55% | 7% |
| Pan Atlantic Research | March 4–13, 2019 | 500 (LV) | ± 4.4% | 25% | 27% | 48% |
with Generic Republican and Generic Democrat
| Poll source | Date(s) administered | Sample size | Margin of error | Generic Republican | Generic Democrat | Other / Undecided |
| Siena College/NYT Upshot | September 11–16, 2020 | 663 (LV) | ± 5.1% | 41% | 53% | 6% |
| Quinnipiac University | September 10–14, 2020 | 1,183 (LV) | ± 2.9% | 40% | 53% | 7% |
| Fabrizio Ward | July 29–31, 2019 | 600 (LV) | ± 4.0% | 43% | 42% | 15% |

### Results

Like many Republican Senate candidates in 2020, Collins did much better on Election Day than pre-election polls predicted; nearly all of them predicted her defeat. Collins defeated Gideon in the general election with 51.0% of the first-place votes, precluding additional rounds of tabulation. Gideon conceded to Collins on November 4.
United States Senate election in Maine, 2020 :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | Susan Collins (incumbent) | 417,645 | 50.98% | −17.48% |
| | Democratic | Sara Gideon | 347,223 | 42.39% | +10.89% |
| | Independent | Lisa Savage | 40,579 | 4.95% | N/A |
| | Independent | Max Linn | 13,508 | 1.65% | N/A |
| | Write-in | Write-in | 228 | 0.03% | -0.01% |
| Total votes | Total votes | Total votes | 819,183 | 100.0% | N/A |
| | Republican hold | Republican hold | Republican hold | Republican hold | Republican hold |

#### By county

By county :
| County | Susan Collins Republican | Susan Collins Republican | Sara Gideon Democratic | Sara Gideon Democratic | Lisa Savage Independent | Lisa Savage Independent | Max Linn Independent | Max Linn Independent | Write-in | Write-in | Margin | Margin | Total votes |
| County | # | % | # | % | # | % | # | % | # | % | # | % | Total votes |
| Androscoggin | 32,979 | 56.19 | 22,181 | 37.79 | 2,438 | 4.15 | 1,090 | 1.86 | 2 | 0.00 | 10,798 | 18.40 | 58,690 |
| Aroostook | 24,033 | 67.51 | 9,750 | 27.39 | 1,072 | 3.01 | 743 | 2.09 | 3 | 0.01 | 14,283 | 40.12 | 35,601 |
| Cumberland | 74,592 | 38.45 | 105,308 | 54.29 | 11,907 | 6.14 | 2,138 | 1.10 | 39 | 0.02 | -30,716 | -15.83 | 193,984 |
| Franklin | 9,817 | 56.47 | 6,276 | 36.10 | 969 | 5.57 | 322 | 1.85 | 0 | 0.00 | 3,541 | 20.37 | 17,384 |
| Hancock | 17,371 | 49.19 | 15,379 | 43.55 | 1,821 | 5.16 | 736 | 2.08 | 8 | 0.02 | 1,992 | 5.64 | 35,315 |
| Kennebec | 39,481 | 54.92 | 27,664 | 38.49 | 3,407 | 4.74 | 1,324 | 1.84 | 10 | 0.01 | 11,817 | 16.44 | 71,886 |
| Knox | 11,705 | 45.44 | 12,190 | 47.32 | 1,461 | 5.67 | 399 | 1.55 | 3 | 0.01 | -485 | -1.88 | 25,758 |
| Lincoln | 12,075 | 51.08 | 10,102 | 42.73 | 1,111 | 4.70 | 349 | 1.48 | 3 | 0.01 | 1,973 | 8.35 | 23,640 |
| Oxford | 19,567 | 58.54 | 11,705 | 35.02 | 1,511 | 4.52 | 635 | 1.90 | 4 | 0.01 | 7,862 | 23.52 | 33,422 |
| Penobscot | 51,088 | 59.96 | 28,958 | 33.98 | 3,461 | 4.06 | 1,600 | 1.88 | 100 | 0.12 | 22,130 | 25.97 | 85,207 |
| Piscataquis | 6,603 | 66.95 | 2,655 | 26.92 | 394 | 3.99 | 210 | 2.13 | 0 | 0.00 | 3,948 | 40.03 | 9,862 |
| Sagadahoc | 11,558 | 48.08 | 10,787 | 44.87 | 1,354 | 5.63 | 337 | 1.40 | 3 | 0.01 | 771 | 3.21 | 24,039 |
| Somerset | 17,861 | 64.92 | 7,355 | 26.73 | 1,770 | 6.43 | 525 | 1.91 | 3 | 0.01 | 10,506 | 38.18 | 27,514 |
| Waldo | 12,538 | 51.57 | 9,768 | 40.18 | 1,604 | 6.60 | 394 | 1.62 | 9 | 0.04 | 2,770 | 11.39 | 24,313 |
| Washington | 11,196 | 64.56 | 5,251 | 30.28 | 547 | 3.15 | 338 | 1.95 | 10 | 0.06 | 5,945 | 34.28 | 17,342 |
| York | 64,092 | 49.46 | 57,826 | 44.63 | 5,389 | 4.16 | 2,255 | 1.74 | 16 | 0.01 | 6,266 | 4.84 | 129,578 |
| Overseas | 1,089 | 19.28 | 4,068 | 72.02 | 363 | 6.43 | 113 | 2.00 | 15 | 0.27 | -2,979 | -52.74 | 5,648 |
| Totals | 417,645 | 50.98 | 347,223 | 42.39 | 40,579 | 4.95 | 13,508 | 1.65 | 228 | 0.03 | 70,422 | 8.60 | 819,183 |

#### By congressional district

Collins won one of the two congressional districts in the state, which also elected a Democrat.
| District | Collins | Gideon | Others | Representative |
| 1st | 44% | 49% | 7% | Chellie Pingree |
| 2nd | 59% | 35% | 6% | Jared Golden |

## Analysis

Gideon underperformed Biden by 10.6%, the second-worst underperformance by a Democratic Senate candidate in the country. Examples of this discrepancy include Wells, a coastal town in the state's liberal southwest corner, where Biden won by 14% and Collins by 6%.
During his presidency, Collins's stance on Trump waffled, as he did not share her moderate politics but had a strong base in Maine's sprawling, rural 2nd congressional district. Collins voted against the Affordable Care Act repeal, but for the GOP's 2017 tax bill and to acquit Trump in his first impeachment. She voted to confirm Trump's nominees Brett Kavanaugh and Neil Gorsuch to the Supreme Court but against the confirmation of Amy Coney Barrett just days before the 2020 election, citing disagreement with process.