More than 1.1 million people could vote in Massachusetts state primary, Galvin predicts

As many as 850,000 people could file Democratic ballots by Tuesday’s state primary, but Secretary of State William F. Galvin said he doesn’t expect voting to reach the record levels it did during the 2020 primary.Pat Greenhouse/Globe Staff/file

As many as 850,000 people could file Democratic ballots by Tuesday’s state primary, and more than 300,000 more could vote in Massachusetts’ Republican primary races, the state’s top elections official estimated Thursday — turnout that would exceed the last time the governor’s office was on the September ballot.

Secretary of State William F. Galvin, who himself is facing a primary challenge in Tuesday’s vote, said he doesn’t expect voting to reach the record levels it did during the 2020 primary. That year, 1.4 million voted in Democratic races, and 1.7 million cast ballots overall during the early depths of the COVID-19 pandemic.

But, he said, expanded mail-in voting, now permanent in Massachusetts, has been “remarkably successful” this year, with 700,000 people requesting ballots.

It could help drive up turnout for a primary that has many factors working against it. The primary itself is scheduled for the day after Labor Day, voters have no congressional primaries to weigh in on, and there’s just one active primary — among Republicans — for the open governor’s office.

Galvin said of the roughly 376,000 people who have already voted, more than 50 percent are not enrolled in any party. And about 22 percent of those so-called independent voters have requested a ballot for GOP races, which typically tend to be more insular and draw heavily from the pool of roughly 460,000 registered Republicans in the state.

“I think that’s politically significant,” Galvin said.

Geoff Diehl, a former state representative and Donald Trump-backed conservative, is vying for the GOP gubernatorial nomination against Chris Doughty, a Wrentham businessman and first-time candidate.

In 2018, when Governor Charlie Baker and Senator Elizabeth Warren were both running for reelection, nearly 982,000 voters voted in that September’s primary, including 700,000 in Democratic races.

Galvin, a seven-term Democrat, is estimating between 800,000 and 850,000 will submit a Democratic ballot this time, and “in excess of” 300,000 will on the GOP side, figures that hinge largely on how many people ultimately return mail-in ballots and, particularly in urban areas, show up the day of the primary to vote.

“That’s my best guess. And I must say, it is a guess,” Galvin said, calling it one of the “hardest times” he’s had projecting turnout given the various ways people can vote — early in-person voting ends Friday — and the lack of top-of-the-ticket races on the Democratic side.

Attorney General Maura Healey is the Democratic Party’s presumptive nominee after her last opponent, state Senator Sonia Chang-Díaz, ended her campaign in June. (Chang-Díaz’s name is still on the ballot.)

The Democratic ballot includes several other primaries. State Senator Eric P. Lesser, Salem Mayor Kim Driscoll, and state Representative Tami L. Gouveia are vying for the nomination for lieutenant governor and to be Healey’s running mate in the November election. Leah Allen, who has positioned herself as Diehl’s running mate, and Kate Campanale, who’s been running with Doughty, are running in the Republican ticket’s lieutenant governor’s race.

Andrea Campbell, a former Boston city councilor, and Shannon Liss-Riordan, a labor attorney, are battling in a tightening Democratic primary for attorney general. Tanisha Sullivan, the president of the NAACP’s Boston branch, is challenging Galvin for secretary of state, and two Democrats — state Senator Diana DiZoglio and transportation advocate Chris Dempsey — are running for the party’s nomination for state auditor.

Polls are open Tuesday from 7 a.m. to 8 p.m. Galvin is encouraging anyone who has yet to return a mail-in ballot to do so at a ballot drop box or to their local clerk’s office, warning that with just days to go until the Tuesday vote, it may not reach election officials in time if mailed.

Those who have submitted a mail-in ballot can track whether their local clerk’s office received it on the Secretary of State’s website.

More than 4.7 million people were registered to vote statewide as of last year, according to the Secretary of State’s office.