U.S. Rep. Conor Lamb, a Democratic candidate for the U.S. Senate from the suburbs of Pittsburgh, planted a pair of political flags — geographical and ideological — in Southeastern Pennsylvania Wednesday.

Lamb was unanimously endorsed by the Philadelphia Building & Construction Trades Council, 30 labor unions in the city and surrounding suburbs with the political heft to help his campaign with manpower and money.

Ryan Boyer, the Council leader who also heads the Laborers District Council, made clear in his introduction that Lamb’s position on organized labor and the fracking of natural gas in the state, made him their clear choice.

“He understands that we work in the energy industry, that we want to protect the environment, but we also want to protect our jobs,” Boyer said. “And Pennsylvania has a perfect solution for energy, a bridge fuel, natural gas.”

Lamb, who pledged to also make sure President Joe Biden’s infrastructure plan adheres to provisions that provide work for union members, also took a not-so-veiled shot at the presumptive Democratic primary front-runner, Lt. Gov. John Fetterman.

“I view this campaign as a job interview,” Lamb said. “You kind of forget that sometimes, I think, from the way some of the other campaigns are run. It’s about entertainment and it’s about identity and it’s about social media. It’s not.”

Lamb, in an interview after the event, said the unions chose his experience over the rest of the field, including Philadelphia State Rep. Malcolm Kenyatta, Montgomery County Commissioners Chair Val Arkoosh and Kevin Baumlin, an emergency room doctor.

“None of them have experience beating Republicans in tough races,” he said. “That’s the experience that I bring to this. And I think that’s what this vote recognizes. These people want to win. Their members don’t have the luxury to be ideological about politics. They’re very practical.”

Lamb has won multiple races in conservative-leaning congressional districts, including a 2018 special election in a district former President Donald Trump had carried by 20 percentage points.

Lamb’s endorsement lays claim in the state’s largest city, where Kenyatta has hoped to capitalize on his connection to the city with the largest swath of Democratic votes.

And Lamb, seeking to negate the narrative that the Democratic primary is divided between progressives and moderates, casts himself as the candidate for blue-collar workers, a key constituency sought by Fetterman, a self-styled progressive populist.

National Democrats are watching closely: Pennsylvania’s Senate race is likely their best chance to gain a seat in the chamber, and it could help determine who has a majority and the keys to Biden’s agenda after this year. The incumbent Republican senator, Pat Toomey of Lehigh County, isn’t seeking reelection.

Lamb released his first digital ad last week, heavy with hardhat-wearing blue-collar workers and rhetoric comparing the U.S. Constitution to labor rights in the workplace. Lamb, in the ad, says those rights “are under attack like never before.”

“Our democracy was born here, as much in the coal mines as in the Constitution,” Lamb said in the ad.

It was a callback to Lamb’s entry to the race in August at a Pittsburgh union hall, where he launched with backing from 18 labor groups, including the Laborers from the western side of the state.

Lamb in many ways has modeled his campaign after Biden, who launched his 2020 bid in a Pittsburgh union hall. Lamb, like Biden, has shown a reliance on backers from the Democratic establishment, while Fetterman has tried to emphasize grassroots support.

Chris Borick, director of the Muhlenberg College Institute of Public Opinion, sees shades of U.S. Sen. Bob Casey’s statewide races as well, which have made the Scranton Democrat successful not just in places where his party has numbers on their side.

“When you think about the infrastructure of Democratic politics in Pennsylvania, unions still matter in the bones of the party,” Borick said, calling Lamb’s endorsements “significant” because they establish him as a player in Southeastern Pennsylvania.

At the same time, recent elections have shown that union endorsements don’t always translate to votes from rank-and-file members, who often break from their leadership.

It’s nice that the building trades are there, that’s wonderful but are those actually people that vote for him?” political strategist Mustafa Rashed said.

Rashed noted that the building trades are arguably the city’s largest union prize in terms of money and political clout, but it’s not necessarily an indicator of where all union support will go. Unions have become increasingly less monolithic politically. While the building trades backed Lamb, service unions, which have leaned more progressive in politics in recent years, may go elsewhere.

One of the city’s largest unions, District Council 33, which represents all nonclerical city workers, is backing Kenyatta, his campaign announced Tuesday. Kenyatta also has the support of the Philadelphia Federation of Teachers and 1199c, which represents hospital and nursing home employees in the city.

Wednesday’s endorsements set a parallel to the 2016 Democratic Senate primary, when Katie McGinty was the establishment candidate winning support from building trades and other unions on her way to endorsements from the state party and then-President Barack Obama.

McGinty won the 2016 primary but lost her bid to unseat Toomey. Fetterman, who finished third that year, had cast himself as a progressive outsider, willing to shake up his party and the Senate.

He’s now more established in state politics, as a statewide elected official, yet still carries himself as a political outsider, cultivating a persona that has thrilled a legion of grassroots supporters but puts him at odds with longtime party players and even some fellow elected Democrats.

“I never talk to him,” said former U.S. Rep. Bob Brady, who has chaired Philadelphia’s Democratic Party for three decades. “He’s never called me in my life.”

Brady, in an interview this week, said Lamb came to visit him at the party’s headquarters two weeks ago.

Hours before Lamb’s event, Fetterman posted his own show of strength, announcing more than a week ahead of the deadline for the next campaign finance reports that he had raised $2.7 million in the final three months of 2021, and had $5.3 million in the bank as of Dec. 31, a figure likely to overshadow everyone else in the Democratic field.

He received 98,000 donations in October, November and December, a number indicating the reach of his appeal.

“I could not be more proud that our momentum and grassroots support is only growing heading into 2022,” Fetterman said in a news release.

He has also previously touted his endorsements from unions representing steelworkers and food workers across the state, and has been regularly showing up at picket lines to support striking workers in places like Erie, Scranton and Lancaster.

Arkoosh, meanwhile, has backing from the national Democratic women’s group EMILY’s List and has pointed to support from a number of suburban elected officials.

There’s also still a lot of institutional support up for grabs in Philadelphia. It remains to be seen if the union endorsements will have a domino effect. But Philadelphia’s traditional Democratic establishment has also shifted, said state Sen. Anthony Hardy Williams, who is undecided in the race.

“The establishment historically meant the Democratic machine, the party ... the unions and people who’d been around a while. That population is declining. Even the progressives have factions,” Williams said.

“The bottom line is for a person coming from a place they’re not in, getting a huge group putting boots on the ground there is a big deal,” Williams said. “It doesn’t translate to people knowing him yet but it does give him an opportunity to get known.”