Boston Mayor Marty Walsh kicked off his second term with a populist flourish Monday, outlining an ambitious agenda focused on preserving economic mobility and aiding the city’s most vulnerable residents — a socioeconomic call to arms that came with a pointed biographical twist.

“My parents came here as immigrants with next to nothing,” Walsh said. “My father got a job helping to build Boston’s growing skyline. He and my mother were able to make a home, to raise their two sons to dream even bigger dreams. That’s the kind of progress a strong middle class provides: not just security for those who are already comfortable, but opportunity for all those who need it.”

“My greatest concern for our city’s future,” Walsh added, “is that we could lose this engine of upward mobility.”

For anyone who followed Boston’s recent mayoral race, these comments struck a familiar chord. Throughout the 2017 campaign, Tito Jackson, Walsh’s challenger, argued that Boston was becoming a city of haves and have-nots, and that policies crafted by Walsh in his first term were largely to blame.

Walsh, however, offered a different diagnosis in his inaugural address, saying that recent Republican-led changes in tax and healthcare policy have effectively left the nation’s middle class under attack from Washington, DC.

Boston, he suggested, can fight back in a way that makes the city an example for the rest of the country.

“We can be the city that’s world-class because it works for the middle class,” Walsh said.

How, exactly? In Monday’s speech, Walsh said the starting point is bettering Boston’s public schools — improving their infrastructure, creating what he called “simpler grade configurations,” and expanding an existing food-service pilot program “until every single student in our district gets two fresh, nutritious meals every single day.” That goal drew applause from the audience packed into Emerson’s 1,200-seat Cutler Majestic Theater downtown.

But Walsh also argued, essentially, that the city can’t go it alone when it comes to making public education an effective springboard for Boston’s students. He urged local colleges and universities to create 100 new scholarships for BPS students, and local employers to do a better job finding untapped talent among low-income residents of Boston’s neighborhoods.

In addition, Walsh promised to aggressively expand Boston’s affordable housing stock over the next four years. He defended his administration’s record in this area to date — “we have seen rents stabilize” thanks to aggressive new construction, Walsh said — but he acknowledged that more needs to be done, in Boston proper and the Greater Boston region as a whole.

“Too many families,” Walsh said, “are still being priced out of too many neighborhoods. We are determined to meet this challenge by redoubling our efforts.”

Also drawing sustained attention from the mayor Monday: new approaches to homelessness and addiction recovery in the city.

At one point, the mayor made a dramatic vow to rebuild the bridge to Long Island, in Boston Harbor, which was closed in 2014 and forced the relocation of several programs aiding the homeless and individuals grappling with chemical dependency. (At the time, Walsh suggested the bridge would be rebuilt, but subsequently seemed to back away from that commitment.)

“For many people, including myself, Long Island played a vital role in Boston’s landscape, and it will again,” Walsh said, alluding to his own recovery from alcoholism. “I pledge to you today that we…will rebuild the bridge back to Long Island, and we will create on Long Island the comprehensive, long-term recovery campus that our city and our state needs now more than ever to tackle the opioid crisis.”

Walsh also announced a new push to raise money for permanent, supportive housing for Boston’s chronically homeless residents. Dubbed the Boston’s Way Home Fund, it’s slated to create 200 new units of housing over the next four years through $10 million dollars in private donations.

“Boston built America’s first public school, first public park, and first public library,” Walsh said. “We dug the first subway, invented the first telephone….  Now, let’s be the first major city to come together as community and end chronic homelessness for good.”

Such calls to a benevolent, Boston- or Massachusetts-based exceptionalism usually play quite well in the Commonwealth, and Walsh’s inaugural was no exception. If anything, the audience at the Cutler Majestic seemed especially receptive to the mayor’s summons. One possible explanation: some artful priming from former Vice President Joe Biden, who presided over the ceremony and suggested, in his own remarks, that Boston has a special role to play in the Trump era.

“It’s about possibilities — it’s about really believing anything is possible,” Biden said in his speech, which preceded Walsh’s. “That’s America. That’s Boston.”

Later, after citing an urgent need for local leaders who “stand up against the ugly divisiveness” of the political present, Biden closed on a more upbeat, crowd-pleasing note.

“The rest of the nation looks to you,” Biden said. “Folks, you’re a remarkable city with a remarkable past and an unlimited future. And as my grandfather, Ambrose Finnegan, used to say, ‘This is a match made in heaven, Marty Walsh and Boston.’”