In the waning days of a tumultuous legislative session in Montana’s Capitol, Carl Glimm, a state senator and a member of the ultraconservative Freedom Caucus, watched with exasperation as yet another Democratic-backed bill zoomed toward passage.

“Are we not embarrassed?” Mr. Glimm asked from the Senate floor in Helena. “This thing’s a big red ‘No,’ but I’ll tell you what — it’s going to be 23-27,” he added, predicting his own defeat. “Because, like we’ve said before, the cake is baked.”

In deep-red Montana, Republicans have controlled both houses of the Legislature since 2011, and the governor’s office since 2021. They ousted the last remaining Democratic statewide official, former Senator Jon Tester, in November.

Which has made it all the more aggravating for conservative lawmakers to find themselves effectively in the minority this year.

After an intraparty dispute in January, nine Republican state senators began breaking with their caucus on key votes, siding with the 18 Democrats in the 50-person chamber. The result: a 27-person majority that has all but locked Republican leaders out of power.

Some or all of the Nine, as the Republican defectors are known, have voted with Democrats to reauthorize a Medicaid expansion, establish a child tax credit, increase access to maternal health care and pass the state budget. They have helped block bills that would have weakened labor unions, made state judicial elections more partisan and established an unlimited hunting season on wolves.

On Wednesday, the session’s final day, they again broke with their party, pushing through a property tax cut to assist residents struggling with soaring home values.

The unusual alliance shows that for all the seeming unanimity in the MAGA movement, Republicans can still clash over policy objectives and the wielding of power. And in an era when advancing legislation often loses out to mocking the opposing party, it shows that some on the right remain more interested in getting things done.

But it could prove something of a blip: a reversion to bygone reflexes toward compromise belying Montana’s steady drift to the right.

Former Gov. Brian Schweitzer, a Democrat, said politicians elsewhere could learn from the Nine.

“What they’ve done is said, ‘I’m going to vote with the people I represent back home — and that’s not what the party leadership is telling us,’” Mr. Schweitzer said.

“We’ll haul Congress out here to see how it’s done in Montana,” he joked, adding that he would “put in the first $50” for bus fare.

Policy over party

The Nine argued that they were simply prioritizing smart policy over ideological conformity — reauthorizing the Medicaid expansion would keep open rural hospitals in their districts, for instance — and supporting the agenda pushed by Gov. Greg Gianforte, also a Republican.

But as President Trump exerts near-total control over the Republican Party, and the country seems bitterly divided along partisan lines more than ever, the G.O.P. schism in Montana has attracted outsize attention.

As the session progressed, other Montana Republicans ramped up a pressure campaign against the defectors, posting their photos on social media, demanding that they quit bucking party leadership and giving them nicknames like the “Nasty Nine.” In March, Republicans tried to expel one of the heretics, Jason Ellsworth, from the Legislature over alleged ethical violations; a majority of Democrats helped block the attempt.

The Montana Republican Party even censured the Nine, saying they would no longer be considered Republicans or receive funding from the state party because of “the damage they have exacted on the Montana Senate.”

The Nine remained upbeat. Days before the legislative session ended, seven of them sat for an interview in the State Capitol, describing praise from voters, swapping stories of admonishment by local Republican groups and declaring that such criticism had only strengthened their resolve.

“I always looked at politics when I was younger and you see people work across the aisle,” said Gayle Lammers, a first-term senator. “I know we’re in this new age where division is so hardcore, but why can’t we get back to where any reasonable legislation is reasonable legislation? If it’s good for Montana, if it’s good for your district, why not consider it?”

Even though they have voted with Democrats, the senators say they remain conservative Republicans and strong supporters of Mr. Trump. All of them voted for a bill restricting transgender people’s use of public bathrooms, and most of them sided with their Republican colleagues on several anti-abortion bills. Josh Kassmier, who emerged as a leader of the Nine, noted that he had sponsored a bill cutting the income tax, a move backed by Donald Trump Jr.

Since Mr. Gianforte took office in 2021, Mr. Kassmier said, “we’ve cut the budget, we’ve made government more efficient — that’s all Trump politics, right?” He added: “We’re voting on the policy. It’s not a deal we’ve made with the Dems.”

One of the Nine, Wendy McKamey, keeps at her desk a stack of notes from Montanans thanking the group for its courage. “Give ’Em Hell,” the front of one card reads, above an image of a cowgirl astride a galloping horse.

“They help me own my vote,” Ms. McKamey said. “I will not offend my conscience.”

Though the Legislature’s political lines seemed blurred, some lawmakers and analysts suggested the real rift was between those who wanted to make policy and those who sought to obstruct it.

“It’s about who is more interested in governing, really,” said Jessi Bennion, a political science professor at Montana State University. Montana’s right wing, she said, seemed less interested in conservative fiscal policy than in introducing controversial bills on social issues that jammed up the legislative process.

That put hard-liners on a collision course with Mr. Gianforte, who did not endorse Matt Regier, the right-wing Senate president, last year but did endorse a group of relative moderates. The Freedom Caucus issued a rebuttal to Mr. Gianforte’s State of the State address in January, suggesting that Montana should spend less money than the governor desired and opposing some of his priorities, like Medicaid expansion.

Mr. Gianforte has avoided speaking directly about the Nine, and a spokesman for the governor declined to comment. But he has seemed pleased to have achieved many of his goals.

Intense blowback

Despite the recent rightward drift, Big Sky Country has long been proud of its independent streak and small-town values. Montana has voted for a Democratic presidential candidate only once since 1964 — Bill Clinton in 1992 — but it had Democratic governors and senators for decades.

In previous legislative sessions, which occur every two years, a loose coalition of Republicans called the Solutions Caucus worked with Democrats to pass bills. But that was easier for Republicans to swallow when a Democratic governor made it necessary to compromise.

What stood out about this year’s bipartisanship was the animosity it produced.

The conflict started the first week of the legislative session, when the Nine were assigned to what they say was a sham committee that would have sidelined them from the legislative process — part of an effort, they argued, to make it easier for Mr. Regier and his allies to consolidate power.

The senators pushed back, agreeing with Democrats on alternate committee assignments. From there, they said, the Democrats were only too happy to work with the Nine on some bills.

In an interview, Mr. Regier called the bipartisan alliance a “gut punch.” He said none of the Nine had raised concerns about committee assignments when Republicans met before the session, and suggested the unhappiness was a “talking point” that provided “cover for them to side with Democrats.” Efforts to win them back, he said, had been rebuffed.

“We tried and tried,” Mr. Regier said. “It was obvious to see there was some sort of handshake, friendship, collaboration with the Democrats.”

Mr. Regier denied that right-wing Republicans were obstructionist and sounded dumbfounded by the Nine’s role in locking them out of the legislative process. “You’re scratching your head being like, ‘Are you even on our team anymore?’” he said.

He also argued that the unlikely alliance was out of step with the electorate.

“Voters want more and more conservatism here in Montana,” Mr. Regier said, suggesting the episode amounted to “growing pains in becoming more conservative.”

Democrats also felt heat for their role in the coalition — from the left. Bill Lombardi, a former top aide to Mr. Tester, faulted the Democratic senators for voting with Republicans on issues like maintaining a tax on Social Security.

“While working together is good, you can’t give away Democratic principles,” Mr. Lombardi said. “Republicans have cemented their position in Montana, and some legislative Democrats think they must hew to the moderate Republican line to get anything.”

But the frustration appears more strongly felt on the right.

Theresa Manzella, a founder of the Freedom Caucus, said right-wing state senators had tried hard to get the Nine to back down but eventually tired of the fight.

“We’ve resigned ourselves to life in the circus,” she said. “And, unfortunately, it is our circus, and these are our clowns.”