Rep. Diane Russell, D-Portland,at the Maine Democratic State Convention in May. Troy R. Bennett | BDN

It was April 16, the final night of this year’s legislative session, and Diane Russell was disgusted.

The House had just approved an agreement about how to spend $21.5 million that Maine was awarded in a 2015 settlement with a Wall Street ratings agency. The deal supported a sales tax exemption for the agriculture sector, Jobs for Maine Graduates, rate increases for mental health service providers and anti-drug programs. It garnered support from Gov. Paul LePage and Republicans by sending $10 million to the state’s rainy day fund.

Russell, after a fiery speech on the House floor decrying how the bill had bypassed vetting in the legislative committee process, was one of 26 Democrats and an independent who voted against the measure. It was the latest in a series of issues in which Russell has put herself at odds with establishment Democrats and legislative leaders in her party.

“That was maybe my final act as a legislator and I have never felt more wrong about what the House just did,” she said to the Bangor Daily News on her way out of the State House that night. “It was wrong.”

She told the Bangor Daily News that night that it was among the most grievous things she’d seen happen in the House — made all the worse because it was possibly her last action as a lawmaker.

As it turns out — other than votes she later cast on veto day — that might have been Russell’s final act as a lawmaker. Having lost a bitterly fought primary battle on Tuesday for a Maine Senate seat representing part of Portland, Russell’s future in elected office is uncertain, especially after she finished third in a three-way race behind Rep. Ben Chipman, who won endorsements from Senate Minority Leader Justin Alfond and other notable Democrats, and Dr. Charles Radis, a political newcomer.

But is the fact that she butts heads with leaders within her party the reason why?

“My philosophy has always been to go big or go home,” Russell said Thursday in an interview with the Bangor Daily News. “On Tuesday I went home. … I knew the establishment was going to come after me.”

Russell’s downfall came after she had become one of the more widely known and visible House members in recent memory because of her advocacy for legalizing recreational marijuana and implementing ranked-choice voting in Maine — both of which will appear as citizen-initiated referendums on the November ballot.

Russell further increased her profile earlier this year when she led the way to a vote at the Democratic State Convention to do away with the Democrats’ system of letting superdelegates support who they want for president regardless of who wins the Maine Democratic Party’s nomination process. On top of it all, she’s proven she’s potent when it comes to raising campaign money. Her $89,000 haul for the Senate primary was among the highest ever raised for a legislative primary in Maine.

Most of the speculation about why Russell lost on Tuesday has to do with pending complaints to the Maine Ethics Commission against her, Chipman’s quality as a candidate, the negative tone of some of her campaign mailings against him, and Alfond’s scathing criticism of her campaign a day before the election when he endorsed Chipman.

Russell said a combination of those factors could have been at play, as well as a low voter turnout that could have thrown the nomination to anyone in the race. However, she said many in the Democratic establishment have had a target on her back and that it became obvious last year when legislative leaders put her on the Taxation Committee after she had served years on the Veterans and Legal Affairs Committee.

For a four-term representative and member of the majority party in the House, an assignment to a non-leadership position on a committee that was not one of her top choices was a rebuke from leadership. A number of Democrats who had served less time in the House than Russell scored more influential committee assignments.

Russell said Thursday that party leaders continued to try to punish her during her primary campaign for the Senate District 27 seat.

“I knew that the establishment was going to come after me,” she said. “I don’t belong in a kitchen and I don’t kiss rings. I lost because there was a coordinated effort to stop me.”

Democratic House Speaker Mark Eves declined to address Russell’s committee assignment but said in a written statement Thursday that lawmakers are not punished for their positions.

“While I’ve been speaker, every member has been encouraged to vote their conscience and to express their own opinions,” he said.

Alfond declined to comment for this post but in his endorsement announcement, said his reason for choosing Chipman was because he objected to tactics linked to Russell’s campaign.

“The actions by Rep. Russell and her campaign are beyond the pale,” he wrote. “Rep. Russell and her allies have stooped to the worst kind of political tactics.”

Those tactics included a mailer from Russell’s campaign that attacked Chipman for switching from an independent to a Democrat in 2015 and included a picture of Chipman reviewing his own campaign literature during a House session.

Russell said that in the long run, she’ll be remembered for major accomplishments.

“There were a lot of people who volunteered their time on my campaign because of my work on the superdelegate issue,” she said. “You lose a state Senate primary but then you go on to completely devastate the power structure of the Democratic Party at the national level. I wanted to win the Senate seat but in the grand scheme of things in terms of outcomes of what I’ve accomplished in my life, I have the opportunity to change the way we elect our presidential nominee. I have an opportunity to make sure that every voice is heard for generations to come.”

Will she run for office again?

“I am just trying to get my coffee this morning,” she said. “I don’t have a five-year plan. That’s not how I operate.”