He’s ping-ponged across the Merrimack Valley, knocking on doors and canvassing neighborhoods. His volunteers are preparing to hit the phones to reach voters, and internal polling shows a vast majority of Democrats in the Third District view him favorably.
Mayor Martin J. Walsh, though, is no candidate. He just may be the state’s most active campaign surrogate this year.
As his former chief of staff, Dan Koh, runs for Congress, Walsh has taken on an increasingly visible role in the campaign, putting his name and popularity behind the first-time candidate in towns and cities far from Boston’s borders.
Walsh has already knocked on doors in Hudson and Fitchburg in recent weeks, and his longtime partner, Lorrie Higgins, tapped the mayor’s volunteer network, asking them in an e-mail to consider helping in the district. Koh’s campaign, too, has promoted the two-term mayor’s presence, even as some warn of leaning too heavily on an elected official who, no matter how popular, doesn’t serve any of the district’s 37 towns and cities northwest of Boston.
“Dan’s the reason why I’m working extremely hard for Dan,” Walsh said in an interview. “The issues he’s working on — jobs and education — are important to the Third District, but they’re also important to the city and to the whole Commonwealth.”
Walsh emphasized that any efforts to support Koh are at the whim of his mayoral schedule, including when he helped lead a canvass in Fitchburg on June 23 before returning to Boston for, among other things, an appearance at a 100th birthday party.
Koh’s campaign website has highlighted his attendance at events in seeking volunteers, and, in December, it ran an internal poll, finding that 80 percent of Democratic primary voters in the Third District view the mayor favorably, compared with 9 percent who did not.
Walsh plans to return to the congressional campaign trail this weekend “and beyond,” according to an e-mail that Higgins, a fund-raising consultant, sent to Walsh supporters last month.
The mayor’s volunteers are also hoping to organize a phone bank in Boston, according to the e-mail, which was obtained by the Globe. (A Walsh spokeswoman said this week it was still in the process of being set up.) Koh’s campaign noted it has already held dozens of its own phone banks, including in Koh’s hometown of Andover, where he moved and established his campaign headquarters after more than three years of working for Walsh in Boston.
Koh, 33, is one of 10 Democrats vying for the party’s nomination on Sept. 4, in what is the largest primary of any county, state, or federal race in Massachusetts this year.
“Being from and raised in this district and caring so much about it, providing a good job reference is something that I’m honored that the mayor is willing to do,” Koh said.
Walsh — who has set fund-raising records and garnered national attention in rebuffing President Trump — downplayed his role on the trail, saying he’s “just another volunteer knocking doors for Dan.” Koh’s campaign also pointed to nearly 20 endorsements he’s received from current or former officials in the district.
“He’s certainly not depending on me,” Walsh said.
Others still see him as a valuable campaign chip.
To knock on a door and say, “ ‘I’m Marty Walsh, mayor of Boston,’ that’s going to be a very, very big key for Dan. That’s definitely a door-opener,” said Joseph Byrne, a Democratic state committee member from Fitchburg who has not committed to any of the Democrats running in the Third District, and who first met Walsh in the 1990s.
“It’s definitely a conversation starter,” he said.
After his tenure with Walsh, a former labor leader, Koh has also scored endorsements from more than 20 labor organizations. Only state Senator Barbara L’Italien, with 19 union pledges, appears to have garnered a similar share of labor support among candidates in the race.
“Working with the carpenters when he was chief of staff to the mayor gives him a leg up on some of the other candidates in the race,” said Thomas Flynn, the executive secretary-treasurer of the New England Regional Council of Carpenters, which is backing Koh.
But in a congressional district that has famously been thorny to outsiders, trotting out the support of a mayor who doesn’t represent the voters you’re wooing can be a delicate balance. Aides to Walsh and Koh have downplayed the role the mayor had in Koh’s early fund-raising, when donors with Boston connections gave heavily to his campaign.
“We want people who can bring the bacon back to Fitchburg,” said Mike Hurley, vice chairman of the city’s Democratic committee, who said he’s “leaning toward” supporting another candidate, Lori Trahan, but hasn’t formally decided.
“We want to have people say, ‘I know you’re here and we hear you,’ ” he said, adding of Koh and Walsh campaigning together: “I think they can deliver that message, but I’d be a little bit careful to make sure it didn’t backfire on them. I don’t know how much Marty Walsh knows about what is going on in the city of Fitchburg.”
For his part, Walsh said he’s encountered nothing but a great reception in the Third District. He pointed to a previous weekend in Hudson, where he said he met a man raised in Roxbury. He went to the Higginson-Lewis School, and the two struck up a conversation about the city, Walsh said.
“A lot of the people I come across recognize me from the news, and they’re excited. A lot of them have ties to Boston,” he said of the district.
He also denied that his willingness to step into other races, be it for Koh or in backing US Representative Michael Capuano in his own primary fight, is designed to shore up support if he, one day, would seek an office bigger than City Hall.
“There is no IOU,” Walsh said. “I support people because I believe in them. This is about supporting somebody who you think is the best candidate for the job, and I know Dan would do an incredible job.”