Bill Galvin and secretary of state challenger Tanisha Sullivan battle at Democratic primary debate

William F. Galvin and Tanisha Sullivan.

Secretary of State William F. Galvin and challenger Tanisha Sullivan on Monday offered clashing views of the role of Massachusetts chief election officer, pitting the incumbent’s experience against Sullivan’s more sweeping vision of an office Galvin has led for nearly three decades.

The Boston Democrats repeatedly criticized each other during an often bitter hourlong radio debate, their first ahead of the Sept. 6 primary.

Sullivan, a first-time candidate, corporate lawyer, and president of the NAACP’s Boston branch, painted Galvin as a reactive leader who has had to be dragged into implementing progressive voter reforms during his nearly 28 years in office. Galvin repeatedly accused Sullivan of making “misstatements” and twisting his record, at one point charging that Sullivan’s arguments show an “ignorance of the office and the laws around it.”

“I am not ignorant, and I am not misinformed,” Sullivan said, turning to Galvin within the WBUR studio as she listed her degrees, her “20 years of legal practice,” and work with the NAACP. “I am more qualified and credentialed today than the day you walked into that office.”

“That’s a personal attack,” Galvin said. “When you make misstatements and you make them repeatedly about facts of law and it’s corrected for you and you continue to repeat them . . .”

“I’m not making misstatements,” Sullivan shot back.

Galvin, 71, and Sullivan, 48 have both placed the importance of elections at the forefront of their campaigns, promising to push for greater voter access at a time when voting rights are being curtailed across the country. They also both support implementing election-day registration, something Massachusetts lawmakers dropped from an election laws bill that Governor Charlie Baker signed to make universal voting-by-mail permanent.

And the winner could make history, regardless of who emerges. Galvin is seeking a historic eighth term — no secretary has served more than 28 years — four years after easily fending off another challenge from a Democratic opponent who ran on a more progressive platform.

Sullivan would be both the first woman and person of color to lead an office she says has become “stale.” Democratic Party activists chose the Hyde Park resident as their endorsed candidate at their June convention, four years after Galvin’s last Democratic opponent, then-Boston city councilor Josh Zakim, also won the party’s endorsement.

But while secretary of state contests have become a pitched electoral battleground in the aftermath of the 2020 election and former president Donald Trump’s baseless election fraud claims, the Democratic primary here — the only one in the country involving a Democratic incumbent — has largely flown under the radar.

The Democratic candidates have spent less than $300,000 combined this year, with Galvin scraping less than $42,000 from his $2.1 million campaign account. A June UMass Amherst/WCVB poll showed Galvin leading Sullivan, 35 percent to 21 percent, among roughly 550 Democratic primary voters, but 44 percent said they were still undecided.

Monday’s debate, hosted by WBUR in partnership with WCVB and The Boston Globe and moderated by “Radio Boston” host Tiziana Dearing, showed candidates who underscored differences in stark terms.

Sullivan repeatedly cast Galvin as little more than a nuts-and-bolts administrator, arguing the office demands a more active secretary on a range of issues.

That includes, she said, helping to protect reproductive rights, and she cast Galvin as “anti-abortion,” in an apparent reference to votes Galvin took as a legislator in the 1980s and were used as a cudgel against him in the 2018 Democratic primary. (Galvin said Monday he believes having an abortion is a “personal decision of the woman.”)

“I believe that any issue that is of concern to the American public needs to be of concern to this office,” Sullivan said. “This is a democracy office. This is an office that every day should be looking for ways to expand opportunities for all residents and to clear roadblocks. It has not been doing that.”

Sullivan pointed to all registered voters now being allowed to vote by mail in primaries and general elections, a change that was first passed in 2020 during the throes of the COVID-19 pandemic. Galvin, she said, is too willing to sit “waiting for things to happen.”

“It took a global public health crisis for us to get vote-by-mail here in Massachusetts. That is unacceptable,” Sullivan said.

Galvin defended his record, calling himself a “champion of voting rights” who has overseen record-breaking elections, while repeatedly charging that Sullivan was misconstruing his record and the law.

The Brighton Democrat said, for example, the state had a vote-by-mail option starting in 2016. A law passed two years earlier instituting early voting in the state allowed for an “early vote by mail” option for biennial state elections. It represented a more limited option than what voters have now, and many voters at the time opted to cast a ballot in-person, according to a spokeswoman for Galvin’s office.

The 2020 law, and a bill that Baker signed this year making the expanded option permanent, extended it to primary elections and required the state to send all registered voters a vote-by-mail application.

Galvin also took a dig at Sullivan’s voting record, suggesting she “missed voting in some of the elections” in 2016. Records show Sullivan voted in the March presidential primary and November election, but did not cast a ballot in the September primary that year. Sullivan voted in every other major local and state election since, records show.

“You keep saying that you’re not ignorant,” Galvin told Sullivan. “ . . . Once again, you want to be the chief election officer, but you don’t know election laws.”

Sullivan bristled at Galvin’s characterization, charging that the secretary of state must take responsibility when laws expanding voting rights either inch along or fail to pass on Beacon Hill, including during Galvin’s 27-plus years in office.

“During that time, Massachusetts has not been a leader when it comes to the advancement of voting rights,” Sullivan said. “You are not a friend of the voting rights community. You are not a friend of the civil rights community. You find yourself on the other side of justice all the time.”

While overseeing elections, the secretary of state’s office also enforces the state’s public records law, polices the state’s financial industry, and is a clearinghouse for corporations registering with the state, among other duties.

The winner of the Democratic primary will move on to November to likely face Rayla Campbell, a Whitman Republican who, too, is running to be the first Black woman to hold the office.

Campbell opposes universal mail-in balloting, and backs implementing an ID requirement to vote. She has also sown doubts about the 2020 election, suggesting in April that the media “buried the truth.”