“He connects, his voice resonates and they know he’s got a track record of performance on their behalf,” said Harold Schaitberger, the president of the national Firefighters union, which offered its endorsement of Mr. Biden on Monday.
Asked what Mr. Biden brings to the primary, Mr. Schaitberger swept out his hand to a few hundred firefighters and other union members, mostly white, who had gathered on Pittsburgh’s Market Square for a midday worker’s service: “All these people right here.”
But Pittsburgh offers a glimpse at Mr. Biden’s challenges as well as his opportunities. The city, its work force and its politics are all rapidly changing.
This is no longer the steel-producing industrial powerhouse of yore. Health care, technology and the sciences now drive the economy. And while the United Steelworkers union is still based downtown, and claims the most local members of any labor group, the more diverse, service-industry unions are growing.
Even the choice of venue for Mr. Biden’s appearance illustrated the city’s transition. When he appeared before hundreds of firefighters and building trade members at a well-worn Teamsters hall, he was standing in a thoroughly gentrified neighborhood, Lawrenceville, that’s home to a ramen joint, a number of boutiques that trumpet their female ownership and, naturally, a hipster coffee shop.
The region is also undergoing a political realignment. While the old steel and coal towns outside Pittsburgh are turning toward the G.O.P., the affluent enclaves that were once full of Republicans, as well as many Steelers and Penguins coaches and players, are now tilting toward Democrats.
It was Representative Conor Lamb’s margins in some of these upscale precincts that propelled him to surprise special election victory a year ago here and Democrats just won a special State Senate race thanks to some of the same voters.