U.S. Senate hopeful Malcolm Kenyatta scored a big union endorsement Wednesday that echoes the state representative’s central campaign message as the working-class candidate with a working-class background.

SEIU Pennsylvania, which represents 80,000 workers — including health-care workers, security guards, and food-service employees around the state — backed Kenyatta at a news conference outside City Hall attended by members clad in their signature purple and yellow, holding “Labor for Malcolm” signs.

“The question people ask is: Can he win?” SEIU president Gabe Morgan said. “I guess what I’m curious about is why you think someone who does not represent what most working-class people and Democratic voters in the state want can win?”

There’s been a flurry of endorsements in the Senate Democratic race as the May primary nears. U.S. Rep. Conor Lamb was in the city Tuesday to get Mayor Jim Kenney’s backing; he had already been endorsed by the Philly building trades. Kenyatta previously won the support of the city’s largest municipal workers union, the Working Families Party, and the American Federation of Teachers. Montgomery County Commissioner Val Arkoosh has the backing of Emily’s List, which works to elect Democratic women. Lt. Gov. John Fetterman secured early on the backing of the statewide steelworkers union and the United Food and Commercial Workers Local 1776.

State Sen. Sharif Street, who had explored a bid for the U.S. Senate, confirmed Wednesday that he would not be running. That leaves Kenyatta as the most prominent candidate from Philadelphia in the race.

Endorsements are one piece of a much more complex campaign puzzle, but they can signal building strength.

The service workers’ union is one of the biggest union endorsement prizes in the state because of its political organizing capabilities and campaigns for workers’ rights issues such as raising the minimum wage and paid leave.

In the 2016 Senate primary, SEIU backed Katie McGinty, but it hasn’t consistently endorsed in the years since.

Lamb, Fetterman, and Arkoosh had also sought the SEIU endorsement. Morgan said that the union has worked well with the other candidates but that ultimately, Kenyatta’s backstory and message resonated most with members.

“We think it’s important for there to be a candidate that people want — not just someone you’re voting for because you’re afraid of what happens if the other person wins,” Morgan said. “Our union has learned that the only way you can do anything for the working class is if you will fight when people tell you there’s an unwinnable fight.”

Several members of the union, including a nursing home worker and a security guard, spoke at the endorsement event near the Harriet Tubman statue.

“Poor and working-class Pennsylvanians are tired of hearing empty promises from politicians who can’t personally relate to them,” said Nina Coffey, a caseworker who helps people file for public assistance.

Kenyatta, a second-term state representative and third-generation North Philadelphian, spoke about the struggles of his mother, who worked as a home health-care aide. He recalled her having to ask herself if she should stay home and help her children with their homework or go work another shift “so they have lights to do the homework under.”

“Too many people have to make that choice,” he said. “These members understand that choice.”

Kenyatta’s fund-raising has significantly lagged some of the other rivals for the nomination. But he said for those who have written off his campaign, the endorsement shows he can excite a key portion of the base. “This race is not just between two white guys from Pittsburgh,” he said, referring to Fetterman and Lamb.

“It’s time for us to say it’s no longer good enough for a politician to just ask for your vote. We need to elect people who understand your life.”