The2026 United States Senate election in Maine will be held on November 3, 2026, to elect a member of theUnited States Senate to represent the state ofMaine. IncumbentRepublican SenatorSusan Collins, first elected in 1996, is running for re-election to a sixth term in office. If elected, Collins will become the longest-serving U.S. Senator from Maine, surpassingWilliam P. Frye on May 26, 2027.
This will be the only Republican-held Senate seat up for election in 2026 in a state thatKamala Harris won in the2024 presidential election. Collins is the only incumbent Republican senator in any of the 19 states thatDonald Trump did not win in any of his three elections. It is expected to be one of the most competitive races in the Senate election cycle.[1]
Collins was first elected in1996, and was re-elected in four subsequent elections, significantly outperforming other Republicans in the state. In2020, despite almost all polls and analysts predicting that she would lose her re-election bid, Collins unexpectedly defeated Democratic nomineeSara Gideon by about nine percentage points. Democratic presidential nomineeJoe Biden carried Maine by about nine percentage points on the same ballot.[5]
As the only Republican-held Senate seat up for election in a state thatKamala Harris won in the2024 presidential election, and Collins' record of over-performance, despite the state's Democratic lean, Maine is considered a key Senate battleground in 2026. This Senate seat has been held by Republicans since1979, when Collins' predecessor, RepublicanWilliam Cohen, defeated incumbent DemocratWilliam Hathaway. Cohen's victory over Hathaway is the last time an incumbent U.S. Senator has been defeated for re-election in Maine. A Democrat has not been elected to the U.S. Senate from Maine sinceGeorge J. Mitchell was re-elected in1988 and from this seat since Hathaway was elected in1972.[a]
With the decline ofticket splitting, and being in a mid-term year with a Republican president, Collins is widely viewed as the most vulnerable incumbent Republican senator.[6][7] Following the retirement ofJoe Manchin inWest Virginia, and the defeats of Democratic senatorsJon Tester inMontana andSherrod Brown inOhio in2024, Collins remains the last senator to represent a non-swing state of the opposite party (i. e., a reliablyred or blue state).[8]
Collins was first elected in1996, and has served five consecutive terms.[9] While she has the firm backing of national Republicans,[10] two conservative Republicans are challenging Collins in the primary.[11] PresidentDonald Trump will not endorse Collins, but has no plans to endorse any candidates in the race.[12]
In April 2025, Jordan Wood became the first Democrat to announce his Senate candidacy. Wood previously worked as chief of staff to U.S. RepresentativeKatie Porter, and helped lead theEnd Citizens United political action committee (PAC).[26][27] On August 19, 2025, Sullivan Harbor MasterGraham Platner announced his candidacy,[28] receiving the support of organized labor and Vermont SenatorBernie Sanders.[29] Progressive and younger Democratic senators, such asElizabeth Warren,Chris Murphy,Sheldon Whitehouse, andAndy Kim, also expressed support for Platner's candidacy, while stopping short of endorsing in the primary as of February 2026.[30][31] Term-limited GovernorJanet Mills was seen as a potential candidate to challenge Collins for months, with national Democrats like the Senate Minority LeaderChuck Schumer, SenatorKirsten Gillibrand, and theDemocratic Senatorial Campaign Committee (DSCC) encouraging her to run,[32][33][34][35] although others, such as Sanders, publicly discouraged her from running.[36] Leaked campaign documents in early October indicated that Mills was set to enter the race shortly,[37] and Mills officially announced her campaign on October 14.[38][39] Mills would be the oldest freshman senator in history, at 79 years old at the start of the term should she be elected, causing some to express concern about her age.[40][39] Mills said she plans to serve one term should she be elected.[41] Several other Democrats also announced campaigns. After Mills' announcement, Democratic candidates Dan Kleban and Daira Smith-Rodriguez withdrew their candidacies and endorsed Mills.[42][43] The DSCC and Mills formed a joint fundraising committee for her campaign leading to backlash and allegations of undue favor towards Mills in the primary from the Senate Democratic leadership.[44][45][46][47][48]
Shortly after Mills entered the race, Platner came under fire for resurfaced controversialReddit posts, resulting in his campaign's political director, former state representativeGenevieve McDonald, quitting the campaign and calling Platner "unelectable"; however,Democratic National Committee ChairKen Martin stated that the comments were not disqualifying,[49] 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 theTotenkopf used byNazi Germany'sSchutzstaffel. Platner stated he got the tattoo while inebriated with otherU.S. Marines while stationed inCroatia, mistaking the symbol for askull and crossbones. He had thetattoo covered,[50] and professed his shame and disgust for getting a tattoo that resembled the fascist insignia.[51] Platner also called himself an anti-fascist "supersoldier" in an old Reddit comment.[52] Senator Murphy defended Platner in an interview and said that he "sounds like a human being" who is honest about his mistakes.[53][54][55] SenatorRuben 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 "cryptoFetterman".[56][57]
On November 12, Wood withdrew from the race to insteadrun for theU.S. House of Representatives seat inMaine's 2nd congressional district after incumbent DemocratJared Golden announced he would not seek re-election.[58] On December 4, candidate Daira Smith-Rodriguez terminated her campaign and endorsed Mills after Platner's previous comments appearing to minimize the issue of sexual assault in the military. A survivor of sexual assault during her time with theU.S. Air Force, she stated that she "cannot, in good conscience, indicate support or remain silent if there is even a possibility that someone who questions the reality of this crisis could be elevated to the United States Senate".[59] On January 10, Platner announced that he would be pausing his campaign temporarily in order to be with his wife, who would be undergoingin vitro fertilisation treatment inNorway.[60] He had returned to Maine and resumed his campaign by January 23, leading several protests againstOperation Catch of the Day, the Trump administration's surge ofImmigrations and Customs Enforcement (ICE) agents into Maine, and against the killings ofAlex Pretti andRenée Good, who were killed by ICE andCustoms and Border Protection agents in related immigration enforcement activities inMinneapolis, Minnesota.[61]
^Independent SenatorAngus King, who has represented Maine in the Senate since 2013, has caucused with theSenate Democratic caucus for his entire tenure, and has not faced a major Democratic opponent since his first election, but is not an enrolled member of the Democratic Party.
^Held office as a Democrat until becoming an Independent in 2024
^abcdefKey: A – all adults RV – registered voters LV – likely voters V – unclear
^Kondik, Kyle (December 5, 2024)."The End of the Line for Red State Senate Democrats".Sabato's Crystal Ball. RetrievedJuly 9, 2025.Collins is now the lone outlier among all 100 senators as someone who continues to hold a Senate seat in a state that hasn't supported her party's presidential nominee in decades. Such outliers were important parts of past recent Democratic Senate majorities, but they will now be all gone.
^Clarke, Bill."Home".Bill Clarke for US Senate. RetrievedJanuary 8, 2025.11/17/25 - Having "tested the waters", and not secured the support I had hoped to at this point, I've decided to end my campaign.
^Hart, Benjamin (October 16, 2025)."Graham Platner's Honeymoon Is Over".Intelligencer. RetrievedOctober 17, 2025.Whether Platner can surmount any fallout from the posts may depend on how well he can incorporate them effectively into his regular-guy image — and whether there is more from his past to be exposed. One good sign for him: Two of his backers in the Senate seem unperturbed so far:
^abDavis, Emma (September 3, 2025)."Maine Beer Company founder joins race against Susan Collins".Maine Morning Star. RetrievedSeptember 5, 2025.After launching his campaign, Kleban announced later Wednesday Maine Senate President Mattie Daughtry and Lucas St. Clair, national board chair of the Trust for Public Land, as his campaign co-chairs.
^Razor, Calen; Carney, Jordain (October 9, 2025)."Graham Platner has a growing Senate fan club".Politico. RetrievedOctober 9, 2025.King said Wednesday that his general practice is not to campaign against colleagues, and he expects to stick with that next year — including not endorsing in the primary.
^Wardwell, Faith; Kashinsky, Lisa; Howard, Andrew (November 12, 2025)."Maine Democrat drops Senate bid for battleground House run". RetrievedNovember 19, 2025.Wood declined to endorse in the Senate race following his withdrawal but said he'd "support whoever the Democratic nominee is."
