PITTSBURGH — Pennsylvania’s U.S. Senate race just got even more competitive.

The Friday campaign launch by moderate U.S. Rep. Conor Lamb likely finalized the Democratic field, solidified the early contours of the race, and set up a direct clash with the perceived early front-runner, Lt. Gov. John Fetterman, an unabashed progressive from the same home county.

Lamb, a Democrat who gained prominence in 2018 with a long-shot victory in Western Pennsylvania Trump country, immediately became a top contender and the party’s first major candidate with a centrist profile, adding a new element to a race that could determine control of the Senate — and with it, the fate of President Joe Biden’s agenda.

It’s also shaping up as the latest contest between moderate and progressive Democrats over the party’s policies and tenor.

Lamb, with a history of winning tough House races, is seen in some circles as the most serious initial rival to Fetterman, though party insiders are also closely watching Montgomery County Commissioner Val Arkoosh, who also has powerful backing, hails from Philadelphia’s vote-rich suburbs, and could benefit if the two Western Pennsylvania contenders divide their region’s votes.

State Rep. Malcolm Kenyatta, of Philadelphia, has won some notable endorsements and comes from the state’s largest city, but has struggled to raise the money likely needed for a statewide campaign.

Lamb’s supporters see him in the same mold as Biden: a candidate who has shown he can appeal to the moderate and swing voters who can be critical in a state as delicately balanced as Pennsylvania. He has won three House races in districts that leaned slightly or heavily right — one had backed former President Donald Trump by 20 percentage points — and there were clear parallels with Biden Friday. Yet some of the same stances that helped Lamb in past races could become obstacles with the more liberal electorate in a Democratic primary.

While he and Fetterman represent opposite ends of Democrats’ ideological spectrum, they have each laid claim to being able to win crucial labor union support and some of the white, working-class voters who have recently fled the Democratic party.

» READ MORE: How Democrats' 2022 U.S. Senate field is taking shape in Pennsylvania

Lamb, 37, illustrated that effort Friday when he opened his campaign outside an electrical workers’ union hall on Pittsburgh’s Hot Metal Street. Behind him stood a crowd of local officials and union members, including some in yellow T-shirts reading “Firefighters for Lamb.”

“We go everywhere, we talk to everyone,” Lamb told a modest crowd in his opening speech, describing his strategy and jabbing at the exaggerated influence the far left can have on social media. “It is not something we can do with tweets and slogans.”

He talked about fighting racial inequality and climate change, but mostly focused on the Republican Party and its attempts to overturn the 2020 election result and impose new voting restrictions. Democracy, he said, “is on the line.”

“If they will take such a big lie and place it at the center of their party, you cannot expect them to tell the truth about anything else,” Lamb said in a message geared toward Democratic primary voters.

He said nothing about his Democratic opponents. Talking to reporters, he pointed to the results that come when Democrats prioritize winning. He said they passed “the most progressive piece of legislation” in his lifetime — Biden’s $1.9 trillion stimulus bill — because Biden won the White House and the party held the House majority by reelecting people like himself.

“So if what we’re interested in as progressives is making progress in real life, it looks like we found a formula to do it,” Lamb said.

While Fetterman has emphasized his grassroots support, as illustrated by his massive support from small-dollar donors and fervent social media following, Lamb rolled out support from unions, elected Democrats, and party officials.

Lamb’s $1.77 million campaign fund is second among Democrats to Fetterman’s $3.07 million.

» READ MORE: Here’s what fund-raising reports from Pa.’s 2022 Senate candidates tell us

Biden also held his first major campaign event at a Pittsburgh union hall. Biden also campaigned on the idea that the country’s “soul” was at stake. Biden also leaned heavily on endorsements from establishment figures. Biden also faced skepticism from some on the left. And Biden also broke with his party’s most progressive voices, playing down the political picture painted on social media.

Allegheny County Executive Rich Fitzgerald, who endorsed Lamb and introduced him Friday, said in an interview, “We want to win.” He added, “If you’ve got a candidate who’s too far left, we won’t win the seat.”

The county, home to Pittsburgh — and Pennsylvania’s second-largest concentration of votes — has provided Fetterman with a strong base of support in his previous statewide campaigns. But Lamb provides an established rival there.

Jack Snyder, a retired electrician who attended Lamb’s launch, said he liked Fetterman, but Lamb has “the right persona” for the race. “I’m tired of all the fighting in politics,” said Snyder, 67.

Fetterman hasn’t criticized Lamb but in recent weeks has blasted moderate Democrats in the Senate, such as Arizona’s Kyrsten Sinema, who have stood in the way of some of progressives’ top priorities, such as abolishing the Senate filibuster.

“Democrats need to vote like actual Democrats and deliver Biden’s agenda to the American people,” Fetterman said in a statement Friday.

While hard-charging progressives often draw the most attention, establishment figures have won a string of major recent victories, including in the primaries for New York mayor, Virginia governor and, this week, a congressional race in Ohio, suggesting the party’s critical mass still leans more toward the center.

Progressives, however, have flexed their muscles in recent years, including in Fetterman’s statewide win in 2018 and the recent primary victory of Philadelphia District Attorney Larry Krasner.

Arkoosh is the only major candidate from the Philadelphia suburbs and has the endorsement of EMILY’s List, an influential Democratic women’s group. She would be the first woman senator from Pennsylvania, while Kenyatta would be the first person of color to represent the state in the chamber.

A number of other newcomers are trying to establish a footing as well.

While Lamb’s centrist appeals might help in a general election, they could rankle some liberal voters in the primary.

He has, for example, said he is personally against abortion, though he has opposed efforts to restrict the procedure, and said Friday he’s “a strong supporter of a woman’s right to choose” and “always will be.”

He was one of just three House Democrats (including Sinema) to vote in 2018 to make the Trump tax cuts permanent for individuals. Lamb has long opposed the tax bill overall, saying it was too weighted to wealthy people and corporations, but said he supported the 2018 proposal because it targeted individuals.

On fracking, a major issue in Western Pennsylvania, he has taken a more moderate stance than others in his party.

“Where I part ways with some critics on the left is I think fracking has been a pretty good thing for our transition to other forms of energy,” Lamb told reporters Friday, saying natural gas has reduced the country’s reliance on coal, though adding that fracking should be better regulated.

» READ MORE: In Western Pa. special election, Dem Conor Lamb aims to shock Trump country

At the same time, Lamb has adopted several more liberal stances as he neared his Senate run. In April, he announced support for banning sales of assault-style weapons, after opposing the idea when he ran in 2018. In May, he said the Senate filibuster “has to go,” contrasting with Biden on an issue animating many on the left.

Lamb’s Senate bid could also have a major impact on the U.S. House, where Republicans need to flip just five seats to win the majority. Lamb’s run for Senate will remove a proven incumbent in a competitive district.