Progressive champion Summer Lee enters primary to replace retiring Rep. Mike Doyle

It became an open-seat race when Doyle announced on Monday that he would not seek reelection next year.

But the precise challenge ahead for Lee is unclear, as redistricting is expected to re-write the borders of a district that currently encompasses Pittsburgh and some of its suburbs and as additional candidates consider entering the contest, which already includes law professor Jerry Dickinson. Despite the uncertainty, Lee is hopeful that the region will continue its recent trend of electing progressive outsiders -- a run of success for the left in Western Pennsylvania that she and a close ally, state Rep. Sara Innamorato, were instrumental in sparking when they ousted a pair of longtime statehouse incumbents in 2018 primaries. In May, progressives scored another big win when state Rep. Ed Gainey, whom Lee endorsed early and organized behind, defeated two-term Pittsburgh Mayor Bill Peduto for the city's Democratic mayoral nomination.

Doyle, first elected in 1994 and the dean of the Pennsylvania House delegation, announced plans to retire at the end of his term less than 24 hours before Lee kicked off her campaign, which had been rumored for some time. Her Federal Election Commission paperwork came in before Doyle made official his plans to depart. His decision spares him a potentially competitive primary. In an interview, Lee called Doyle's announcement a "pleasant surprise," but insisted her message would not change.

"It's one thing to believe in something ideologically, to understand the need for health care for all, to understand the need for a sustainable economy. It's another thing to live it," Lee said. "And I think that that's the thing that we need to see more in races like this -- the lived experiences and the perspective that comes from living out these policy decisions."

She also expressed some concern over the shape of the district she hopes to represent as its lines are redrawn. In his retirement speech, Doyle said he expected the process to "push part of it outside Allegheny County." There will be no incumbents running in either the 18th or neighboring 17th Districts next year, with Democratic Rep. Conor Lamb running for Senate instead of reelection to the House. Lee said she was worried that Pittsburgh might be sliced and diced.

"When you split the second largest population of Black and brown folks in the Commonwealth, when you split the second largest urban area, that's also a gerrymander," she said. "But I will say that whichever way our district grows, we know our region. And I think that we are able to play in this region, whatever district or two districts come out of it."

Doyle on Monday said he believed the time had come "to pass the torch to the next generation" of leaders, but only after pointedly insisting he had "no doubt" that he would have won another term if he sought it. The timing of his announcement, he added, was designed in part to broaden the field of potential replacements.

"There are many people who might not consider running if they thought I was going to run," Doyle said, "so I want to give them the time and opportunity to do so."

Lee was not among those who, as Doyle suggested, might have been cowed by the specter of challenging a longtime incumbent.

"We have a vast district where we've had an incumbent who has rarely faced serious challenges until very recently," she said. "So what that does is it limits the opportunity for new perspectives to come forth and new ideas to be considered."

If she succeeds, Lee told CNN, she is prepared to join forces with the House's increasingly influential Progressive Caucus, which is currently locked in a standoff with moderate and centrist Democrats over the size and scope of President Joe Biden's social spending package, which could include provisions like universal child care, the expansion of Medicare, lower drug prices and an ambitious plan to combat climate change.

Lee said observing the fight from afar has been heartening -- as progressives hold their ground -- and "discouraging," as she pointed to Democratic members who oppose or want to shrink some of the bill's most broadly popular pieces.

"We were sent here to fight for those investments, sent here to fight like hell for our community, our people. We hope that we wouldn't have to, with the majority, fight that way, but it is good to see," Lee said of progressives on Capitol Hill. "Some people say, 'Oh, it's just the Squad,' but this is not that instance. There are more folks in the Progressive Caucus that are fighting ... that's what we need."