As the only Republican senator up for reelection in a state that didn't back Donald Trump in 2024, Maine Sen. Susan Collins was already considered one of the GOP's most vulnerable incumbents headed into the midterms.
Then came an immigration enforcement surge last month targeting some of Maine's largest and most diverse communities.
Department of Homeland Security officials said the surge — dubbed Operation Catch of the Day in an apparent pun on Maine's fishing heritage — would target "the worst of the worst." But eyewitness reports, cellphone videos and news reports suggested the masked, heavily armed agents were taking a much broader reach.
A civil engineer and recent University of Maine graduate from Colombia with a work permit was arrested during his morning commute. Two asylum-seekers legally working at county jails were detained. A month-old baby was showered by glass after agents broke a car window to snag his father, an immigrant with no criminal record.
In stepped Collins.
"I called Secretary [Kristi] Noem because I was very concerned about what I was hearing from constituents and seeing in news reports and ... it also struck me that the term that was being used, 'Catch of the Day,' was highly offensive," Collins told Maine Public Radio last week. "I told her that I felt that ICE officials had gone too far — that they were not focusing on people who are here illegally and had criminal records."
A nearly 30-year Senate veteran, Collins holds arguably one of the most influential positions in Congress as chair of the budget-writing Senate Appropriations Committee. In that role, Collins tried last month to negotiate a funding deal for the Department of Homeland Security (DHS), which includes Immigration and Customs Enforcement.
At that time, Collins said, she "kept pushing [Noem] to suspend and cease the enhanced operations in the state of Maine — and she agreed to do so in response to my request."
Although immigration agents continue to operate in the border state, the highly visible enforcement surge appeared to subside after Collins spoke with Noem. But the senator's critics back home aren't giving her the credit.
"Susan Collins didn't make that happen," said Graham Platner, an oysterman, Marine Corps veteran and Democrat whose progressive Senate campaign has attracted huge crowds since the summer.
Platner argued that the real reason ICE and DHS reduced their presence in Maine is communities organized against them. In fact, Platner blamed Collins for the current situation because, he said, she could have used her influence over federal funding to force the Trump administration to change its tactics.
"I mean, she's done absolutely nothing to stop ICE," Platner said. "She has done absolutely nothing to try to rein in the behavior of the Trump administration over the last year. "
Platner's chief opponent in the June Democratic primary, two-term Gov. Janet Mills, has also made ICE and the immigration crackdown a key campaign issue.
During her State of the State address, delivered several days into the enforcement surge, Mills accused the Trump administration of "stoking fear in our communities ... and arresting people not on public safety grounds but based on quotas, on skin color, on accents, on religion, on ethnic origin."
"We will not be intimidated — we will not be silenced," Mills said. "And to anyone outside these halls, including any federal officials, I say, 'If you seek to harm Maine people, you will have to go through me first.'"
As attorney general and now governor, Mills once had a seemingly friendly working relationship with Collins. But now, the moderate Democrat routinely portrays Collins as being unwilling to stand up to President Trump.
"Right now, she's voting to fund ICE — to continue to fund ICE without any standards, without any substantive controls, without any accountability," Mills told reporters last week. "The people of this country want accountability."
Democratic groups are targeting Collins with the same message. A group tied to Senate Minority Leader Chuck Schumer, who has endorsed Mills, is spending more than $2 million on television and digital ads in Maine hitting Collins on the issue of ICE and DHS funding.
Collins' campaign has called those ads "false and intentionally misleading." Collins also pointed out that the Republican-backed version of the DHS budget bill still stalled in Congress contains about $20 million for body cameras and de-escalation training for ICE agents. The agency is currently shut down as Democrats demand broader reforms within ICE, such as prohibiting masked agents, before approving funding.
In an interview, Collins said it "remains to be seen" whether Trump's policies will be a factor in her reelection bid.
"But I am running on my record of independence," Collins said. "I support the president as I have every other president that I've worked with when I think he is right. I oppose them when I think he is wrong."
The Collins campaign's repeated use of the word "independence" is strategic. Nearly one-third of Maine voters are independents, or unaffiliated, making them the second-largest voting block after Democrats. Those independents have been crucial to Collins' past victories, including in 2020 when she defeated a better-funded Democrat by 9 percentage points.
But Dan Shea, a professor of government at Colby College and a longtime political observer in Maine, pointed out that independents accounted for roughly 40% of Maine voters a few decades ago. Shea said that shift has largely benefited the Democratic Party.
"It's a blue state, but it's becoming more deeply blue," Shea said. "So that's a big issue for the senator. She wins by split-ticket voters, by unaffiliated voters, independents. And that pool is getting smaller."
Shea said Collins will likely campaign hard on her ability to bring home money as chair of the Senate Appropriations Committee. The spending package passed by Congress last month contains more than $300 million in "congressionally directed spending" for Maine that was requested by Collins.
But the bigger headwinds facing Collins and other Republicans, Shea said, is what he projects will be a massive turnout this fall by Democrats motivated by their anger over Trump's policies — with immigration potentially topping that list.
"I think her association with the Republicans in Washington is going to hurt her in Maine," Shea said. "I think she's the underdog. She may win — she's a great campaigner. Again, she's known across the state. But one thing's for sure: I think it's going to be wicked tight."
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