DemDaily: Update on the Senate Landscape! Maine
May 13, 2026
Now halfway into the primary season, the landscape of the 2026 US Senate elections is clear in one of the most critical election cycles in decades -- amid Republicans' razor-thin control of the upper chamb
Midterm elections are almost always a referendum on the occupant of the White House and the party in power, and the 2026 races are no exception. With President Donald Trump's approval ratings at a historic low, the chances of Democrats retaking the upper chamber appear increasingly within reach.
| 35 of the 100 US Senate seats are up for election in 2026, with Democrats defending 13 seats (with four open seats) and Republicans defending 22 seats (including seven open seats). With a 53-47 GOP majority in the Senate, Democrats will need to flip a net four seats to retake the Senate. |
Elections last week in Ohio, Michigan, and Indiana -- where Trump successfully primaried a group of GOP state senators who voted against his midterm redistricting plan -- reaffirmed Trump's stranglehold on the GOP while underscoring the broader and undeniable appetite for electing Democrats ahead of November.
Top Targets
While Republicans are defending a larger share of the 2026 seats, just three of their incumbents -- in Maine (Susan Collins), Ohio (John Husted) and Alaska (Dan Sullivan) are considered among the most vulnerable, along with the open seat in North Carolina being vacated by retiring Senator Thom Tillis.
Among Democrats, the open seats in Michigan (Gary Peters) and New Hampshire (Jean Shaheen), and incumbent Jon Ossoff in Georgia, are the most vulnerable to flipping red.
See: DemDaily: Update on the Senate Landscape! Ohio and Michigan 4/11/26
MAINE
Maine US Senator Susan Collins, the Senate's most vulnerable Republican incumbent, is in the fight of her life -- one that just moved into the toss-up category with the shake-up in the Democratic primary. She is also the only Republican senator facing re-election in a state that Democratic presidential nominee Kamala Harris won in 2024.
A moderate conservative, Collins, 78, has often cast a pivotal vote on key legislation that borders along party lines. With control of the Senate in play, however, flipping the seat is a top priority for Democrats.
While Collins has been re-elected four times in the moderately blue state that otherwise has voted for a Democrat statewide in every presidential election since 1988, her approval rating has hit a record low of 38%.
| Mainers are split-ticket voters with a pattern of electing moderates from both parties, but with a strong Independent voter base larger than the number of registered Democrats or Republicans. |
The Democratic Primary
An original field of eight contenders for the June 9th primary, whittled down to two major candidates in October 2025 with the entrance of term-limited Democratic Governor Janet Mills. Considered a top recruit by national party leaders, Mills won both her gubernatorial races by wide margins.
Sullivan Harbor Master, oyster farmer and veteran Graham Platner, who entered the race in August 2025 with the backing of labor unions and progressive leaders, had already emerged as a key contender.
Platner, 41, positioned himself as an economic populist and outsider fighting against the "Democratic establishment," setting the stage for a contest between the Party's centrist and progressive factions.
Platner, who shares progressive consultants with New York Mayor Zohran Mamdani, developed a large national social media following, drawing large crowds at events and millions in campaign dollars.
The former US Marine, who did three combat tours in Iraq and one in Afghanistan, faced a barrage of ugly revelations in late 2025 about posts he made on Reddit between 2013 and 2021 -- followed by the resignation of senior campaign staff.
In the comments, Platner, who was also found to have a nazi tatoo on his chest, describes himself as a "vegetable growing, psychedelics taking socialist" and a "communist." His early rants were against cops, women, and rural Americans, while advocating political violence and getting "armed."
In October 2025, in an online apology video, Platner assured viewers that the comments did not represent his current political beliefs. They were the product of disillusionment after his military discharge and struggles with PTSD, he said, going on to explain his metamorphosis after coming back home to Maine.
Mills launched attack ads in March 2026, highlighting Platner's controversies -- with little impact. On April 30, after months of trailing Platner in the polls by more than 30 points, she announced that she was suspending her campaign -- saying she no longer had the financial resources to be competitive.
| Platner "embodies a quarter-century of raw American frustration. It's the source of his strength -- and potentially his downfall" - Michael Kruse, Politico, 12/5/25 |
The General Election
Although the candidates will not be their party's official nominees until after the June 9th primary, Mills' withdrawal opened up the general election fundraising floodgates in what promises to be the most expensive statewide race in Maine's history. Combined spending by both parties and outside groups is expected to exceed $400 million.
Platner had already out-raised Collins in the First Quarter of 2026, reporting $4.1 million, for a total of $12 million raised and $2.7 million cash-on-hand. 64% of the political newcomer's contributions were from grassroots donors under $200. His campaign announced an extra haul of $1.5 million in the first week of May.
Collins, who is uncontested in the primary, brought in $3.1 million in the first quarter, for a total of $13.2 million raised, with just over $10 million on hand. Pine Tree Results, a super PAC supporting Collins, reported another $11.5 million in cash on hand.
The incumbent has proven her ability to mobilize a massive nationwide donor network, raising nearly $27 million in 2020 to successfully fend off Maine House Speaker Sara Gideon, who amassed a war chest of $68.5 million. Despite polls showing Gideon in the lead going into the election, Collins defeated her 50.98%-42.39%.
Spending in the 2026 election has been accelerated, with both campaigns and allied groups dropping new political ads in the last 10 days.
The GOP-aligned Senate Leadership Fund has pledged $42 million in Fall television, radio, and digital ad reservations, and conservative nonprofit One Nation has already pumped $15 million into early ad buys and pledged an extra $10 million.
The Democratic Senatorial Campaign Committee (DSCC) and major outside Democratic groups have spent or pledged a combined total of at least $45 million, including a $32 million general election TV ad reservation by the Senate Majority PAC.
| The latest public polling, conducted by Republican firm Echelon Insights April 3-9, 2026, showed Platner leading Collins 51%-45% among likely voters, with 4% undecided (MOE: ± 6.3%). |
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Sources: Politico, The Hill, New York Times, CNN, Newsweek, NYT, Cook Political Report, AP, IE, Sabato, NCSL, NPR, MPR, Bangor Daily News. FEC, Sun Journal, Campaigns, ADMO
