A Democratic primary that will likely determine who becomes Philadelphia’s next mayor could boost a progressive cause struggling to make a comeback after national setbacks, but with no clear front-runner it’s just as likely to fortify the city’s existing Democratic machine.

Not one of the five top candidates has emerged as a clear favorite in Tuesday’s primary, a digression from mayoral races in recent history, said Richardson Dilworth, author of the book “Reforming Philadelphia,” which examines the city’s government over the course of 350 years.

“The political structure of the city is in a moment that is somewhat unprecedented,” he said. “It’s ideologically incredibly cohesive. But … there’s nothing taking that cohesive ideology and converting it into a unified governance for the city.”

The progressive movement — which has focused on local races to counter national setbacks — has its sights on the Philadelphia race after being energized by Chicago Mayor Brandon Johnson’s recent victory and other progressive wins on the St. Louis City Council.

Our Revolution, a movement born during Sen. Bernie Sanders’ 2016 presidential race and now one of the largest progressive organizations in the country, has endorsed Helen Gym, a former member of the City Council. Sanders has also personally endorsed her, and appeared alongside her ahead of the primary, along with progressive U.S. Rep. Alexandria Ocasio-Cortez.

In Philadelphia, “You’ve got an old guard Democratic machine, just like you do in Chicago, although that formation has been rattled within the last couple of years” by successful progressive and Democratic Socialist candidates, said Our Revolution Executive Director Joseph Geevarghese.

Whether Gym can do the same is uncertain.

Philadelphia’s Democratic City Committee — which, in a deeply blue city, can have significant influence — won’t back a candidate. That’s left the choice with the committee’s dozens of independent wards, which aren’t united in their endorsements. Other Democratic factions, meanwhile, are all over the map.

A number of ward leaders, who can rally voters to cast their ballots, have backed the more moderate former city council member and former state lawmaker Cherelle Parker, but others have sided with Gym and former city controller Rebecca Rhynhart, who has sought to appeal to moderates and progressives. The left-wing Working Families Party and the grassroots progressive organization Reclaim Philadelphia, in step with Our Revolution, is backing Gym.

There is even division among unions, which have historically held a lot of weight because of their financial support and their on-the-ground ability to push people to the polls. In a tight contest, that can be essential.

A number of trade and labor unions, which helped propel Kenney when he first ran for mayor, have coalesced behind Parker. Kenney himself said he cast a ballot for Parker during early voting. Meanwhile, the city’s local police union is backing grocery business owner and political outsider Jeff Brown, and the teachers union wants Gym.

Allan Domb, a former councilman and real estate mogul who has poured millions of dollars of his own money into the campaign and sought to appeal to a more moderate-to-conservative base, picked up an endorsement from former Mayor William J. Green III. Rhynhart, meanwhile, is backed by three past mayors: John Street, Michael Nutter and former Gov. Ed Rendell.

All of the candidates, regardless of ideology, have tapped gun violence and public safety as their top concerns. They’ve also discussed a need to bolster the economy, reduce poverty and improve quality-of-life issues such as trash pickup and streetlights.

«The candidates are more or less aligned on most important issues of the day,” said Mark Nevins, a political consultant for The Dover Group. “Really, you’re looking at who has the ability to create a coalition of voters from different parts of the city … that will put them over the top.”

A number of cities have moved to ranked-choice elections, allowing voters to order the candidates from most to least preferred. But in Philadelphia, the winning candidate needs a plurality — which could be just a slim amount of the total vote — to face lone Republican candidate David Oh in the November general election.

In mayoral elections across the nation over the past five years, voters have tended to pick the mainstream liberal candidate, said Robert Speel, associate professor of political science at Penn State. Exceedingly progressive candidates who have called for defunding the police have not done well, he noted; nor have conservative, “tough-on-crime” candidates who seem more aligned with Republicans, including one who lost Boston’s 2021 mayoral race.

“It was a kiss of death for a Democratic candidate in a Democratic city to be associated with Republicans in some way,” he said.

Theresa Tsai, a University City resident who fell in love with Philadelphia after moving here from New York City years ago, is just looking for someone who can work with other city departments to address her issues with crime and what she sees as an overall decline in city services.

Tsai, 71, said she has begun to feel vulnerable in the city while walking alone at night. Years ago, she said, a mini-police station opened in her district, which she said showed her that community policing was critical.

She also said that many city facilities, from libraries to recreational centers, are understaffed. Tsai said her husband keeps a spreadsheet of endorsements, which she is monitoring, and she also wants to hear the recommendation of her ward leader, whom she said she “implicitly trusts.»

At the moment, she is weighing the different qualities that Gym, Rhynhart and Domb could bring to the office.

“This is a difficult election, it really is,” she said. “It’s a good one, it’s good that we have such good choices.”