With Mass. attorney general Democratic primary down to two, crucial question emerges: Who is more qualified?

In a battle between candidates with divergent backgrounds, experts stress that experience is about more than years spent in the courtroom.

Andrea Campbell (left) and Shannon Liss-Riordan, candidates for attorney general, during the Framingham Dems BBQ on Aug. 27.Nathan Klima for The Boston Globe

To be the attorney general of Massachusetts, the “people’s lawyer” as the position is sometimes called, does it matter how much and what type of legal experience a candidate has?

That’s increasingly the focus of the fight between the two Democrats squaring off in Tuesday’s primary to be the party’s nominee for the highest law enforcement position in the state.

One candidate, Shannon Liss-Riordan, has aimed to highlight her two decades of experience as a class-action litigator, calling out the shorter legal résumé of her opponent, former Boston City Council president Andrea Campbell, who has spent more of her career shaping policy than in the courtroom.

Campbell, meanwhile, has said her diverse portfolio of legal experience is only further bolstered by political and lived experience: She has consistently pushed for reforms to the criminal justice system after her twin brother died in custody before his 30th birthday.

The back-and-forth has turned testy at times, and illustrates how heated the race has grown with just days to go before the Sept. 6 primary. A third candidate, Quentin Palfrey, upended the race Tuesday when he abruptly ended his campaign and endorsed Campbell, even though 255,000 voters had already cast ballots. Recent polls showed Liss-Riordan and Campbell in a virtual dead heat.

During a recent debate, Liss-Riordan was quick to call herself “the only practicing lawyer in this race.” Her campaign on Tuesday then released a statement criticizing Campbell’s work for the international corporate law firm Proskauer Rose LLP, which Liss-Riordan said has a reputation for union-busting. She demanded Campbell release the names of clients she represented during her two years at the firm.

Campbell called the demand a “desperate” move to “distract voters and residents from the issues they care about the most.” She noted that Liss-Riordan has yet to make public her tax returns after multiple requests from the Campbell campaign, amid critiques that Liss-Riordan pocketed a significant share of legal settlements she won on behalf of workers.

The exchange, according to some legal analysts, is largely political, an end-game appeal to each’s constituency before polls close. Analysts familiar with the role and responsibilities of the attorney general largely agreed that it’s not the years but the quality of experience that is the best determinant of who is equipped to be the people’s lawyer.

“If you’re sitting there as a lawyer for 25 years, say, representing insurance companies and doing nothing else, the fact you did it for 25 years isn’t really going to make you a better attorney general over the person who may have had six or seven years’ experience out in the community doing something more involved,” said James Tierney, a former Maine attorney general and creator of the educational tool StateAG.org.

Tierney has advised hundreds of attorneys general across the country over the past 30 years and said he has seen firsthand the importance of “strong values and good judgment” over specialized legal experience or a lengthy trial career.

“Whether the AG has any of those experiences is less important than that the AG has the judgment to surround himself or herself with people who have a wide variety of legal skills: trial skills, writing skills, appellate skills, and political skills,” he said. “I can tell you a couple AGs who never practiced law a day in their lives. They were just legislators and ended up being attorney general and they were great.”

While Liss-Riordan is widely recognized for challenging corporate giants, including Uber and Starbucks, Campbell’s record as an attorney is lesser known.

Her legal career began in late 2009, when she was offered a full-time job as an associate at Proskauer-Rose after a summer associateship the year prior. She chose to defer the offer, however, to spend a year working as a staff attorney for the EdLaw Project in Massachusetts, an initiative aimed at dismantling the school-to-prison pipeline by providing free legal services to children involved with the justice system. The initiative is jointly supported by the Youth Advocacy Foundation and the Committee for Public Counsel Services, the state’s public defender agency.

In her role, Campbell worked on a team with a social worker and several other attorneys to handle some of the most sensitive cases of so-called student delinquency, often involving children with learning disabilities that were not being properly addressed by the school.

Joshua Dohan, former board president of the Youth Advocacy Foundation, recalled Campbell’s talent at negotiating between the student, the parents, and the school.

“Andrea really excelled at helping both parties get to, ‘Yes, let’s understand what the young person needs and let’s get it for them,’ ” he said. “But if an agreement couldn’t be made, then she knew how to use the law to make sure the child got what they were entitled to.”

Campbell returned to Proskauer after her year at EdLaw and spent 18 months as an employment attorney before leaving the firm in late 2012, when her twin brother, Andre, died of an autoimmune disease after awaiting trial for two years in a Massachusetts correctional facility.

“I took time to really ask the hard questions: Why am I here? What am I meant to do with my life?” said Campbell, who has long cited the impact of her brother’s death as a driving force in her transition to public service.

The following January, she joined the Metropolitan Area Planning Council as interim general counsel to fill in for an employee on parental leave, according to the council’s human resources office. But just two months later, she was tapped to serve as deputy legal counsel for then-governor Deval Patrick.

“I recall that she had an impressive background, having worked both in the private and the public sector,” said Kate Cook, then-chief legal counsel for Patrick, who hired Campbell in 2013. “She appeared to me to have that kind of legal experience and lived experience that would be a great fit for our team.”

As deputy counsel, Campbell worked on a close-knit team of attorneys who advised the governor on a host of legal matters, from pointing out the potential legal consequences of a new bill to assessing the impact of US Supreme Court rulings on state laws and regulations.

“Andrea brought her legal experience every day, but she also brought her vision and her ability to listen and connect with people,” said Cook, who is now the first assistant for Attorney General Maura Healey.

Liss-Riordan’s legal career took a different path. Years before she made a name for herself as a class-action lawyer, she clerked for a federal court judge in Texas in the late 1990s. Two years later, she joined the firm Pyle, Rome, Lichten & Ehrenberg in Boston, where she got her start in employment law, representing workers. It was during her time there as a partner that she claimed her first legal triumph, a judgment for Massachusetts service workers whose employers were cheating them out of tips. She would claim dozens more, including a multimillion-dollar settlement for Uber and Lyft drivers in a case that challenged the business model of the gig economy.

Liss-Riordan’s reputation recently earned her endorsements from Senator Elizabeth Warren, former Boston acting mayor Kim Janey, and Mayor Michelle Wu, who called the litigator “a people’s champion.”

Campbell has picked up notable endorsements as well, including US Representative Ayanna Pressley. Five of the six still-living Massachusetts attorneys general, including Healey, also endorsed her.

Martha Coakley, who served as attorney general from 2007 to 2015, noted that the office is the only constitutional seat to require that candidates be bar-certified lawyers. But equally important, she said, is a leader who “understands the role government plays in that job, and what it means to be a public service lawyer.”

“The astounding thing about this job is it really requires a set of skills that runs across the board, from management to politics,” Coakley added. “The quality of one’s experience can’t always be measured in years, or by just one thing that you’ve done.”