Boston’s local chapter of the Service Employees International Union has endorsed Acting Mayor Kim Janey’s bid to win a full, four-year term. It’s a move that could improve Janey’s standing among Latino and immigrant voters, add volunteers to her ranks and provide additional campaign funds.

32BJ SEIU, which represents janitors, security officers and custodial workers, has between 5,000 and 6,000 members who are Boston residents and largely Latino, according to union leadership.

Roxana Rivera, 32BJ SEIU vice president, said Janey emerged as the candidate of choice for two reasons: Janey’s life story increases her understanding the challenges members face, and policies Janey has initiated during her brief tenure that demonstrate her commitment to acting on her understanding.

“Like our members, she has experienced racism, sexism and prejudice throughout her life, and she has used that lived experience to fight for justice,” Rivera said, pointing to Janey's June executive order mandating an hourly wage of $14.85 to $20 for city contracts for cleaning and security services.

The pandemic, the inequities it exposed and the need for a strong recovery were high on the minds of union members, Rivera added.

The endorsement comes less than a week after Felix D. Arroyo, Suffolk County register of the probate, and his son City Councilor Ricardo Arroyo — two members of one of Boston's political dynasties — endorsed Janey and canvassed for her in Hyde Park.

The endorsement also follows the exit of State Rep. Jon Santiago — formerly the only Latino in the mayor's race. Santiago, who was attempting to reach Latino voters with multilingual ads and campaign materials, indicated in his withdrawal that he intends to support one of the four women of color in the race.

The union, which supported Felix G. Arroyo’s bid for mayor before backing Marty Walsh in 2013, currently has about $3 million in its state PAC — a figure that could dramatically increase if the group develops a super PAC as Rivera suggested in an interview with GBH News.

"We're still talking through that," she said when asked how much Janey could expect to see in financial support. "We also are going to be most likely looking at doing an [independent expenditure] campaign as well."

The union will also be working to register voters, but its biggest contribution, Rivera said, will be boots on the ground to canvass and phone bank on Janey's behalf beginning July 31 through the September 14 preliminary election.

These endorsements could prove crucial to Janey, who made a relatively late entrance into the race in April and has struggled to assemble a volunteer apparatus to rival that of her opponents. The Boston Herald reported Janey paid people to gather signatures on her behalf.

Union support, which was a united, powerful force for former mayor, now-U.S. Labor Secretary Walsh, has splintered in this election, with some staying on the sidelines so as not to alienate any of the major, politically connected candidates in the field this year.

Rivera told GBH News 32BJ wants to be a part of the historic race dominated by women and people of color.

"We think that we can make a difference," she said.

Correction: An earlier version of this story misidentified the start date for 32BJ’s canvass and phone bank efforts.