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. Republican incumbent Susan Collins is seeking a sixth term. She is being challenged by Democratic former state Senate president Troy Jackson. The election will be conducted with ranked-choice voting.
In the June 9 primaries, Collins was the only candidate to qualify for the Republican nomination. Sullivan harbor master Graham Platner won the Democratic primary over Governor Janet Mills with the support of progressive leaders, but withdrew from the race on July 10 following sexual assault accusations and other controversies. Jackson was chosen to replace Platner via a nominating convention on July 25.
As Collins is the only Republican senator representing a state that President Donald Trump did not win in any of his three presidential campaigns, the race is considered to be among the most competitive in 2026. Democrats have not won a Senate election in Maine since 1988.
Background The election will be held on November 3, 2026, coinciding with U.S. House elections, a gubernatorial election, and other local elections. Both the primary and general elections will be conducted with ranked-choice voting. Incumbent Republican U.S. senator Susan Collins is running for re-election to a sixth term. Both primary elections took place on June 9, 2026.
The northernmost state in New England, Maine is considered to be a moderately blue state. Maine has voted for every Democratic presidential nominee since 1992, and Democratic nominee Kamala Harris defeated Republican nominee Donald Trump by approximately seven percentage points in the 2024 United States presidential election in Maine. Democrats also control the governorship, the state legislature, and both seats in Maine's U.S. House congressional delegation. Since 2018, Collins has been the only Republican representing any New England state in either chamber of Congress.
Collins was first elected in 1996. She has been 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 defeated Democratic nominee Sara Gideon by a nine-point margin. Democratic presidential nominee Joe Biden carried Maine by about nine percentage points on the same ballot.
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. With the decline of ticket splitting, Collins is widely viewed as the most vulnerable incumbent Republican senator in 2026. Collins is also the only Republican senator facing re-election in a state that Kamala Harris won in the 2024 presidential election. Since the 2024 United States Senate elections, Collins has been the last senator to represent a non-swing state (in other words, a reliably Democratic or Republican state) that typically supports the opposing party.
Republican primary Incumbent U.S. senator Susan Collins officially announced her re-election bid in February 2026. Despite Collins receiving backlash from some Republicans for not supporting all of Trump's agenda during his second term as president, the Republican Party nonetheless supports her re-election campaign due to the fact that she is the only Republican who has been electorally successful in Maine in recent years. However, she faced an unsuccessful primary challenge from former police officer Dan Smeriglio, who argued that she votes with Senate Democrats too often. Ultimately, Collins was the only Republican to qualify for the primary ballot.
Candidates Nominee Susan Collins, incumbent U.S. senator (1997–present)
Withdrawn 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
Endorsements
Fundraising Italics indicate a withdrawn candidate Campaign finance reports as of May 20, 2026CandidateRaisedSpentCash on handCarmen Calabrese (R)$17,760$21,260$0.00Susan Collins (R)$14,925,296$6,547,574$9,672,914Source: Federal Election Commission
Polling Poll source Date(s)administered Samplesize Marginof error CarmenCalabrese SusanCollins DanSmeriglio Other Undecided March 1, 2026 Calabrese withdrawsUniversity of New HampshireFebruary 12–16, 2026417 (LV)±4.9%1%67%6%1%25%University of New HampshireOctober 16–21, 2025417 (LV)±4.8%1%66%1%4%27%
Results
Democratic primary 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. In February 2026, Politico described Platner as "unlike any other recent popular candidate the state has seen". Noting Platner's large social media following, Politico added: "He is brash. He is progressive. He has drawn crowds of hundreds of people, national attention and millions in campaign dollars".
After weeks of speculation and leaked campaign plans, Gov. Janet Mills entered the race in October 2025. The DSCC's close involvement in her campaign prompted backlash and allegations of favoritism in the primary.Multiple sources:
Mills was widely viewed as a top Democratic recruit; she was encouraged to run by Senate Minority Leader Chuck Schumer, Senator Kirsten Gillibrand, and the Democratic Senatorial Campaign Committee (DSCC),Multiple sources:
although Sanders publicly discouraged her candidacy.
Following Mills's 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. He returned 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 started a write-in bid for the Democratic nomination.
The Platner/Mills contest 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.
In March 2026, Mills began running attack ads highlighting Platner's controversies. By April 2026, multiple polls had been released which showed Mills as much as 38 points behind Platner in the primary. Shortly thereafter, the Mills campaign 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.
On April 30, Mills announced that she was suspending her campaign, but she did not endorse him. Her withdrawal led to Schumer and Gillibrand announcing they would now help Platner to defeat Susan Collins.
Following the end of Mills' campaign, Platner was the only prominent and competitive Democrat left in the race, making him the most likely Democratic nominee. Mills' name remained on the primary ballot, and Costello also continued his campaign. On June 9, Platner won the primary; he received over 150,000 votes, more than any other Democratic candidate in a primary in Maine's history.
Platner misconduct controversies Shortly after Mills entered the race, Platner came under fire for resurfaced controversial Reddit posts criticizing police officers, calling rural Americans "stupid" and referring to himself as a "communist", 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. Senator Ruben 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's views.
In May 2026, reports surfaced that Platner's wife had alerted his campaign team to explicit messages he was sending to women on the messaging app Kik, expressing concern that the behavior could hurt him politically. Additional reports during the same period drew attention to Platner's Nazi-linked tattoos, as well as past social media posts widely described as bigoted.
In June 2026, The New York Times published an article including allegations of physical abuse and "unsettling" behavior from multiple women. In response, Platner told media that his poor behavior was attributed to PTSD from his service in the Marine Corps. While he specifically denied the accusations made by one woman, he did not dispute the characterization of his behavior toward a second one.
Candidates Withdrew after nomination Graham Platner, Sullivan harbor master
Eliminated in primary 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) Janet Mills, governor of Maine (2019–present) (suspended campaign)
Withdrawn Natasha Alcala, fashion designer David Evans, former Department of Defense policy writer Tucker Favreau, cybersecurity professional 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 (ran for U.S. House; endorsed Platner)
Declined 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)
Endorsements
Fundraising Italics indicate a withdrawn candidate