While Trump and Mills escalated their conflict in public, Collins intervened behind the scenes to shield the state from Trump’s retaliation in several instances, all while maintaining public neutrality and declining to criticize Trump’s punitive approach or call out Mills by name.

The veteran senator’s strategy reflects the uniquely challenging political minefield she is facing not only at a fraught moment for national politics, but at the start of her 2026 reelection campaign.

Collins is hardly Trump’s biggest fan, but she supports his executive order on gender and youth sports and disagrees with Maine’s reasoning for contesting it. At the same time, she is well-known for zealously protecting federal financial support for Maine programs no matter who is in the White House.

Since Trump and Mills’s blowup in front of the cameras, Collins has taken credit for getting the administration to reverse its suspension of a major grant that supports the state’s coastal regions as well as to backtrack on its decision to freeze funds for the University of Maine.

Most notably, Collins intervened in the administration’s most brazen retaliatory act yet against Maine. In March, the acting head of the Social Security Administration, Lee Dudek, moved to deny new parents in Maine the ability to obtain a Social Security card for their newborn by mail. The reason behind the disruptive shift, Dudek later admitted, was that he was “ticked” at Mills for how she spoke to Trump at the White House.

The policy was ultimately reversed — after Collins directly called Dudek to register her alarm, The Washington Post reported. He apologized to her.

For Collins, one of the last GOP centrists in Congress, such awkward middle ground is familiar terrain. But navigating between Trump — who commands and demands the loyalty of Republicans more than ever — and a Democratic governor unexpectedly rising as a national liberal star will pose a fresh challenge for one even as battle-tested as Collins.

“She’s trying to thread a needle,” said Dan Shea, a professor of political science at Colby College in Maine. “The problem is the eye is just getting smaller and smaller.”

The background sound to this maneuvering is the increasing chatter in political circles that Mills could run against Collins next year, a possibility the governor has not ruled out. But Maine politics is a small world, and the two have worked together “in various capacities over the years,” said Garrett Mason, a former Republican majority leader in the Maine Senate who has known Collins for decades.

“Right now, I think they’re tip-toeing around each other,” Mason said. “Senator Collins and [Mills] could be headed to a collision course, or they could be the ones to bridge the divide.”

Meanwhile, some Democrats see Collins’s attempts to contain Trump’s impact on Maine, rather than confront him directly, as untenable. “If you are going to stand up to this administration, it has to be not only in actions but in words,” said April Fournier, a Democratic member of the Portland City Council.

Collins’s office would not make her available for an interview and directed the Globe to her public statements. Ben Goodman, a spokesperson for Mills, said, “The governor is appreciative of Senator Collins’s leadership and partnership on myriad issues facing Maine during this period of significant uncertainty.”

Based on Collins’s public statements, however, she appears eager for the standoff to end quickly. Such a resolution appears unlikely.

In a statement issued Friday, the deadline given by the administration for Maine to begin complying with its executive order, Collins said, “The conflict between how the State of Maine and the Administration interpret Title IX needs to be resolved.” (Title IX is the federal law prohibiting sex discrimination in schools that receive federal funding, which the administration has invoked to support its order banning transgender girls from participating in girls’ sports.)

“I agree with the federal government’s position that biological males should not compete in girls and women’s athletics,” Collins said. “While I will continue to advocate strongly for federal funding for Maine, I disagree with the state’s position and instead support the original intent behind Title IX.”

On Wednesday, Attorney General Pam Bondi announced the administration would sue Maine, claiming “we have exhausted every other remedy” to force Maine into line.

From the beginning Mills has signaled her unwillingness to comply with Trump. She has avoided framing the conflict as a defense of allowing transgender girls to compete, an issue Democrats increasingly feel has harmed them politically, and more as a defense of state sovereignty. Trump and his allies’ heavy-handedness in going after Mills — with the president publicly demanding a “full-throated apology” from the governor in March — has only appeared to steel her resolve. Her administration expressed confidence on Wednesday that it will prevail in court against Trump’s Department of Justice.

While Collins has made clear she believes it’s on Mills to blink first, contending with Trump’s aggressive campaign has practically become a full-time job for the senator.

The trouble began not long after Trump and Mills’s televised spat on Feb. 21. A week later, University of Maine officials said the National Oceanic and Atmospheric Administration notified them it was canceling the $4.5 million Maine Sea Grant, which helps the university fund initiatives related to scientific research and economic development in the state’s coastal regions. The agency gave no reason why, simply saying the grant was “no longer relevant” to the administration’s goals.

Collins then called Commerce Secretary Howard Lutnick — who oversees NOAA — to urge him to reconsider, the senator’s office said. On March 5, a top NOAA official announced the administration would instead renegotiate the grant, “after productive conversations with Senator Susan Collins and her staff.” University of Maine officials also credited Collins for the reversal.

On March 10, the Department of Agriculture announced it was freezing funding for the University of Maine for farming and conservation-related research and youth education initiatives, citing its alleged Title IX violation. By March 13, Collins issued a statement saying the USDA funding had been restored after discussing the matter with the administration.

But Trump has continued his pressure campaign. On April 2, USDA Secretary Brooke Rollins said she was pausing funds that support Maine schools, though she claimed free school lunches for students would not be affected. “This is just the beginning,” Rollins said in a letter to Mills. (Mills called the message “appalling.”)

And on April 8, the Department of Justice announced it was cutting funding for the Maine Department of Corrections because the state incarcerated a transgender woman in a facility for female prisoners.

So far, Collins has appeared to register her concerns privately, tapping into her relationships with Cabinet officials. If she has any issues with Trump’s approach, she has not said so.

“I’m sure, on the inside, it’s not the way that maybe a President Collins would handle this,” said Mason. “She’s doing what she can to make sure Maine isn’t put in a really bad situation.”

Looming over Collins’s interventions is her bid for a sixth term. As she was in 2020, the senator will be a top target for Democrats. To maximize her chances, Collins will need to retain a GOP base that doesn’t tolerate any disloyalty to Trump, while holding on to independent voters who dislike him.

What helps is that Collins has her own brand in the state, defined by her centrist politics and her work to steer federal funds to Maine, a realm where she has even more influence now as chair of the powerful Senate Appropriations Committee. An ironic twist to Trump’s campaign against Mills is that federal dollars supporting Maine programs — some of them hard-won by Collins — have been the collateral damage.

“She is an old-school politician,” said Shea. “That helps bring her across the line in a blue state.”

Sam Brodey can be reached at sam.brodey@globe.com. Follow him @sambrodey.