Over $78 million has already been spent on advertising in Maine’s 2026 U.S. Senate race, which is on pace to smash a state record set in U.S. Sen. Susan Collins’ last campaign.
While the Democratic primary between Gov. Janet Mills and political newcomer Graham Platner rages on, Republicans are spending heavily in an attempt to shore up support for five-term U.S. Sen. Susan Collins. Her approval was 12 points underwater in a Pan Atlantic Research poll released Wednesday.
The five-term Republican was durable enough to withstand a 2020 race in which more than $123 million was spent on advertising during the general election. It had barely begun by this point that year, and this one is starting much differently.
Here are the three major themes in the spending so far.
Republicans are running a traditional pro-Collins campaign.
Collins faced an ad spending deficit early in her race with then-House Speaker Sara Gideon in 2019, when a dark-money group formed to put pressure on the senator on the heels of her vote for U.S. Supreme Court Justice Brett Kavanaugh.
This time is different. Republican groups have reserved more than $45 million in ad time across all platforms tracked by AdImpact to nearly $33 million for Democratic ones. This is giving Collins some cover on political issues from the major ones in the news to more minor ones.
For example, one of the latest ads from One Nation, a leading Republican outside group, calls Collins a “tireless fighter” for rural hospitals. Another one urges people to thank her for helping to ensure Maine has clean water. Baseball and apple pie are next.
Platner is lapping the candidates in ad spending.
The insurgent candidate is the frontrunner in this race if the Pan Atlantic poll is to be believed. His campaign has a canny ad strategy that leans heavily into his progressive policy ideas on social media but has begun to run fairly standard biography ads on TV, including one that began running Wednesday that calls him “the veteran who came back home.”
He is flexing his recent fundraising haul to advertise heavily, spending nearly $3.1 million to date. Mills has only spent $730,000 or so, and Collins has just been running a modest amount of digital ads with the cover she has from outside groups.
Reinforcements are coming for Democrats.
Republicans have come in heavier so far, but the Democratic group WinSenate has been gradually sizing up in Maine this month and has put down $20 million in reservations that largely stretches through the core election season in the approach to November.
National Democrats including Senate Minority Leader Chuck Schumer, D-New York, want Mills to be the nominee. But Platner is looking like he may be able to sustain a major campaign if Democrats pick him in June. His party has few other paths to the majority, so they will likely keep these reservations barring an implosion.


