Update at 5:45 p.m.: WBUR’s David Scharfenberg discusses the endorsements — and the Tuesday bus strike — with host Sacha Pfeiffer:
BOSTON — Former mayoral candidates Felix Arroyo and John Barros are expected to endorse erstwhile rival Marty Walsh at an event in Egleston Square Tuesday, a high-level Walsh campaign source confirmed Tuesday.
The endorsements give Walsh a potentially potent talking point in a fierce contest for Latino, black and ideologically liberal votes.
“I think they’re both very significant” endorsements, said Peter Ubertaccio, a political science professor at Stonehill College. “You have two very prominent young candidates of color… I think Arroyo and Barros are the future of the city.”
Arroyo, a city councilor at large, finished fifth in the 12-way preliminary election for mayor last month. Barros, the former executive director of the Dudley Street Neighborhood Initiative in Roxbury, finished sixth.
Together, they garnered about 17 percent of the vote.
Walsh, a state representative, and City Councilor At-Large John Connolly, the other finalist in the mayoral race, began aggressively courting the 10 also-rans the night of the preliminary election.
The most sought after endorsements: Arroyo, Barros and former state Rep. Charlotte Golar Richie, who made the strongest showings in the black and Latino precincts that have emerged as the chief battleground in a final election.
Golar Richie, who finished third in the preliminary election with 14 percent of the vote, has not yet backed a candidate.
The pressure on her to make a decision will probably mount with the Arroyo and Barros announcements.
The endorsements follow the first independent poll in the race, commissioned by the Boston Herald and conducted by Suffolk University, which shows Connolly leading Walsh 41 to 34 percent.
The survey suggests Walsh, who got a splash of publicity with his first-place finish in the preliminary election, has gained some ground.
He ran 15 points behind Connolly in a hypothetical head-to-head match-up in a Herald/Suffolk poll a month earlier.
In the new survey, Connolly has an edge among black voters. Latinos are evenly split between the candidates.
Ubertaccio says the Arroyo and Barros endorsements give Walsh an opportunity to grow his support in minority neighborhoods. They also send a signal to minority voters “to stay engaged.”
“There’s been a lot of consternation since the preliminary about the fact that there’s no candidate of color in the [final election],” he said. “And we would suspect that some [minority] voters might just opt to stay home. This is an important cue for them.”
The developments come as several prominent black and Latino leaders weigh an endorsement of their own.
The local branch of the NAACP, Latino advocacy group Oiste and liberal umbrella group Right to the City have asked Walsh and Connolly to lay out their priorities on development, housing, public safety, diversity in leadership, education and jobs.
Activists are convening a closed meeting Tuesday night at the Boston Teachers Union headquarters to discuss their agenda for the new mayor and consider an endorsement.
Activist Mariama White-Hammond, a Barros supporter who remains neutral in the Walsh-Connolly contest in the run-up to the Tuesday night meeting, said there is no guarantee the coalition will endorse.
But minority votes, she said, will matter in the final mayoral election next month.
“I think whoever wins communities of color is who is going to lead this city,” she said.
Barros was a little known candidate at the beginning of the mayoral race. But newspaper columnists and mayoral rivals alike praised him for speaking fluidly about poverty and education and calling for a more inclusive city government.
The candidate, who is of Cape Verdean descent, fared best in the precincts along the Dudley Street corridor in Roxbury.
Arroyo, a former union organizer who performed best in parts of Roxbury and his home base of Jamaica Plain, spoke out against the “demonization” of public school teachers and opposed lifting the cap on charter schools.
That put him at odds with both Walsh and Connolly, who support lifting the cap.
But Connolly is more closely identified with an education reform movement that favors charter schools and greater flexibility for principals to hire and fire teachers.
And Walsh, like Arroyo, is closely associated with labor, stepping down from his post atop the Boston Building Trades umbrella group to run for mayor.