2026 United States Senate election in Maine

Susan Collins(presumptive)

TBD

Party

Republican

Democratic | | | | Susan Collins(presumptive) | TBD | | Republican | Democratic | | | | | | | | | | | | Susan Collins(presumptive) | TBD | | | | | | | | | Republican | Democratic | | | | | | | | | Incumbent U.S. senator Susan Collins Republican | Incumbent U.S. senator Susan Collins Republican | | | | | | | | | Incumbent U.S. senator Susan Collins Republican | | | | | | | | |

The 2026 United States Senate election in Maine will be held on November 3, 2026, to elect a member of the United States Senate to represent the state of Maine. Incumbent Republican U.S. senator Susan Collins is running for re-election to a sixth term. This election will coincide with U.S. House elections, a gubernatorial election, and other local elections. The primary is scheduled to take place on June 9, 2026. Both the primary and general elections will be conducted with ranked-choice voting.

This election is expected to be among the most competitive Senate races in 2026. Collins is the only Republican senator who represents one of the 19 states that Donald Trump did not win in any of his three presidential campaigns. This will be the only Republican-held Senate seat up for election in a state that Kamala Harris won in the 2024 presidential election.

The northernmost state in New England, Maine is considered to be a moderately blue state, having voted for every Democratic presidential nominee since 1992, and voting for Kamala Harris by about seven percentage points in 2024. Democrats also control the governorship, the state legislature, and both seats in Maine's U.S. House congressional delegation. After 2018, Collins has been the only Republican representing any state in New England at the federal level, in either chamber of Congress.

Collins was first elected in 1996, and was re-elected in four subsequent elections, significantly outperforming other Republicans in the state. In 2020, despite almost all polls and analysts predicting that she would lose her re-election bid, Collins unexpectedly defeated Democratic nominee Sara Gideon by a 9-point margin. Democratic presidential nominee Joe Biden carried Maine by about nine percentage points on the same ballot.

As the only Republican-held Senate seat up for election in a state won by Kamala Harris in the 2024 presidential election, Maine is considered a key Senate battleground in 2026 despite Susan Collins' history of electoral overperformance. Republicans have held the seat since 1979—the last time a sitting U.S. senator from Maine lost reelection. No Democrat has won a Maine Senate race since 1988, or this seat since 1972.

With the decline of ticket splitting and being in a midterm election with an unpopular Republican president, Collins is widely viewed as the most vulnerable incumbent Republican senator. After 2024, Collins is the last senator to represent a non-swing state of the opposite party (a reliably red or blue state).

Incumbent U.S. senator Susan Collins officially announced her reelection bid in February 2026. Despite conservative backlash to her centrist voting record, the Republican Party has supported her reelection. However, she faced a primary challenge from former police officer Dan Smeriglio, a critic of her bipartisan approach. Ultimately, Collins was the only Republican to qualify for the primary ballot.

• Susan Collins, incumbent U.S. senator (1997–present)

• Carmen Calabrese, restaurant owner

• Bill Clarke, entrepreneur and Constitution Party nominee for U.S. Senate in 1996 and for governor in 1998

• Dan Smeriglio, former police officer

In April 2025, former congressional staffer Jordan Wood became the first Democrat to enter the race, running on a platform opposed to the Trump administration and Elon Musk. On August 19, Sullivan Harbor Master Graham Platner launched a progressive campaign backed by Bernie Sanders and organized labor, positioning himself against the "Democratic establishment" and drawing support from both liberal voters and some 2024 Trump voters.

Governor Janet Mills was widely viewed as a top Democratic recruit, with encouragement from national figures including Senate Minority Leader Chuck Schumer, Senator Kirsten Gillibrand, and the Democratic Senatorial Campaign Committee (DSCC), though Sanders publicly discouraged her candidacy. This primary was seen as a key contest between the Democratic Party's centrist establishment wing and the populist left-wing and progressive faction, with Mills representing the former and Platner representing the latter. Following the end of Mills' campaign Platner was the most prominent and competitive Democrat left in the race, making him the most likely nominee.

During the late 2010s and the 2020s, progressive Democratic candidates have gradually gained ground, with some ousting more traditional Democrats.

After weeks of speculation and leaked campaign plans, Mills entered the race in October 2025, pledging to serve only one term; her age, 79 at the start of the term, drew some scrutiny. The DSCC's close involvement in her campaign, including a joint fundraising committee, prompted backlash and allegations of favoritism in the primary.

Following her entry, several candidates, including Dan Kleban and Daira Smith-Rodriguez, withdrew and endorsed Mills. Smith-Rodriguez cited concerns over past comments by Platner regarding sexual assault in the military. Wood later withdrew to run for the U.S. House.

In January 2026, Platner briefly paused his campaign due to his wife's medical treatment abroad before resuming later that month, returning to the campaign trail with protests against Immigrations and Customs Enforcement (ICE) enforcement actions.

In February 2026, Mills committed to multiple debates ahead of the June 9 primary.

Mills, Platner, and 2024 nominee David Costello qualified for the primary ballot. In addition, University of Maine adjunct professor Andrea LaFlamme is mounting a write-in bid for the Democratic nomination.

Despite multiple controversies, polling has consistently shown Platner leading Mills in the primary and incumbent Senator Susan Collins in a potential general election matchup. In March 2026, Mills began running attack ads highlighting Platner's controversies. By April 2026, multiple polls had been released, which showed Mills 38 points behind Platner in the primary. Shortly thereafter, the Mills campaign had stopped running the attack ads and had made no additional ad purchases across any platform, leading to rumors that she would withdraw from the race. The Mills campaign denied these rumors, saying that the campaign was "full steam ahead" and that Mills was the most electable candidate. Axios reported on April 6 that the Platner campaign had told donors and supporters that they were pivoting their attention away from the primary and towards incumbent Susan Collins.

On April 30, Mills announced that she was suspending her campaign. When asked if she would support Platner if he won the Democratic nomination, she stated "I've always been a Democrat. I always supported the Democratic candidate." Her withdrawal also led to Schumer and Gillibrand announcing they would now help Platner to defeat Susan Collins.

Shortly after Mills entered the race, Platner came under fire for resurfaced controversial Reddit posts, resulting in his campaign's political director, former state representative Genevieve McDonald, quitting the campaign and calling Platner "unelectable"; however, Democratic National Committee Chair Ken Martin stated that the comments were not disqualifying, and Platner apologized in a five-minute video posted to social media. On October 21, Platner released a video of himself dancing and singing shirtless at his brother's wedding, revealing he had a chest tattoo that resembled the Totenkopf used by Nazi Germany's Schutzstaffel. Platner stated he got the tattoo while inebriated with other U.S. Marines while stationed in Croatia, mistaking the symbol for a generic skull and crossbones. He had the tattoo covered, and professed his shame and disgust for getting a tattoo that resembled the fascist insignia. Platner also called himself an anti-fascist "supersoldier" in an old Reddit comment. After the controversies, Democrats such as Senator Chris Murphy defended Platner and said that he "sounds like a human being" who is honest about his mistakes and Senator Gallego called his campaign "authentic" and said that he has "the right to grow out of his stupidity" and is not going to be a "crypto-Fetterman".

On February 26, 2026, Platner quote-tweeted a clip from Donald Trump's 2026 State of the Union Address, criticizing Trump's speech. The clip had been posted by anti-Semitic white supremacist Stew Peters. The tweet was deleted hours later, with a spokesperson for Platner's campaign telling The Hill that they were unaware of Peters' views.

• David Costello, former deputy secretary of the Maryland Department of the Environment and nominee for U.S. Senate in 2024

• Andrea LaFlamme, adjunct professor at the University of Maine (write-in candidate)

• Graham Platner, Sullivan harbor master

• Natasha Alcala, fashion designer

• David Evans, former Department of Defense policy writer

• Tucker Favreau, cybersecurity professional

• Janet Mills, governor of Maine (2019–present)

• Dan Kleban, brewery owner (endorsed Mills)

• Daira Smith-Rodriguez, former civilian contracting officer for the U.S. Air Force (endorsed Mills)

• Jordan Wood, former chief of staff to former U.S. Representative Katie Porter (running for U.S. House)

• Aaron Frey, Maine attorney general (2019–present) (endorsed Mills)

• Jared Golden, U.S. representative from Maine's 2nd congressional district (2019–present)

• Chellie Pingree, U.S. representative from Maine's 1st congressional district (2009–present) and nominee for U.S. Senate in 2002 (running for re-election)

Aggregate polls

• Tim Rich, former restaurant owner

• Phillip Rench, former member of the Maine Space Corporation Board of Directors (2023–2025)

Susan Collins vs. Graham Platner

Aggregate polls

Partisan client

Official campaign websites

• Susan Collins (R)
• David Costello (D)
• Andrea LaFlamme (D)
• Janet Mills (D)
• Graham Platner (D)
• Tim Rich (I)