Mayor Martin J. Walsh will endorse US Representative Michael E. Capuano in his primary fight with City Councilor Ayanna Pressley, inserting one of the city’s most powerful voices into the battle for its largest congressional district.
Walsh is slated to formally endorse Capuano on Sunday in Dorchester, where he’s expected to emphasize the Somerville Democrat’s experience and record in Congress, as well as his potentially elevated perch if Democrats take control of the House this November.
Walsh’s backing is not surprising; he has said for months that he intended to make an endorsement in the race, and he publicly heaped praise on Capuano in the days after Pressley launched her campaign in January.
In a Globe interview, Walsh pointed to his long relationship with Capuano and the congressman’s own support for him during Walsh’s first mayoral run in 2013. (Pressley remained neutral in that race.) He cited the congressman’s long record of working in the region’s interests.
“One thing about Mike is, he’s been the constant voice in fighting for the labor movement and people of color,” Walsh said. “I look at what is the right thing for the city of Boston and the right thing for what’s happening right now. Something has to be said about experience.”
Pressley’s challenge to Capuano has created an intriguing political matchup in the state’s only district where the majority of residents are minorities. The district includes about 70 percent of Boston, as well as parts of Cambridge and Milton, and all of Chelsea, Everett, Randolph, and Somerville.
On policy, little has separated the two progressive Democrats, whose positions on several topics have mirrored each other, at times down to the word. But they’ve pitched themselves to voters in different ways.
Pressley, a 44-year-old city councilor, is a black woman who lives in Dorchester and has touted the new lens she can bring to Congress. Capuano, a 66-year-old former Somerville mayor of Irish and Italian descent, has billed himself as building the relationships needed to deliver for constituents.
Walsh said the election of President Trump has galvanized unexpected political challenges across the country — oftentimes to long-entrenched incumbents — and that he, too, embraces the calls for a “louder women’s voice” and a “louder voice for people of color” in Washington.
But he said he views that need in historically conservative corners of Congress.
“When I think about change, I think about change in Iowa, in Wisconsin, in Michigan, in Florida, in Wyoming — places where, historically, these super conservative people have gotten control [in Congress] and have not advocated for anything besides cutting and hurting the average person in America,” he said.
Walsh also said he believes Capuano can deliver more for the Seventh District than Pressley if reelected.
If the party takes the House majority in this midterm election, Capuano is in line to chair influential subcommittees on both the transportation and finance committees. That, Walsh said, could put Boston, and Massachusetts, in a better position to reap funding and attention for crucial projects.
“You have a Congress that’s become tone-deaf . . . to the average people of America. And we’re positioned to take it back and make some real strong policy changes,” Walsh said of Democrats.
Pressley, he said, would be a welcome voice in Washington and a “good congresswoman, there’s absolutely no question about that.”
“But,” he said, “there’s a difference in being a voice and someone in a leadership position. That makes a big difference about how it benefits Massachusetts.”
Capuano has said he doesn’t intend to make his seniority a campaign issue, arguing the average voter doesn’t delve into the internal workings of Congress. In a separate interview, he embraced Walsh’s support, saying he and the mayor “see the road pretty much the same.”
“It sends a signal to everyone that the mayor and I are working very hard together to fight for them,” Capuano said. “I think it’s important to see that people of like minds stick together.”
Walsh and Capuano are slated to appear together in Uphams Corner on Sunday afternoon to make the announcement, as well as greet volunteers for a signature drive.
In a statement, Pressley adviser Wilnelia Rivera said her campaign is focused on reaching voters and building its organization.
“Over the past few weeks, we have heard the encouraging voices of support from people in this district who see themselves in this campaign . . . including many who have chosen this moment to be involved in politics for the first time,” Rivera said. “Their stories, and the urgency of their challenges that too often go unheard, is what continues to propel this campaign forward.”