Big progressive names are lining up behind Helen Gym. Will it give her a boost in the Philly mayor’s race?

The progressive star power is rolling in for Helen Gym.

Leading national progressive lawmakers, including Sen. Bernie Sanders, (I., Vermont), have backed Gym’s mayoral campaign, part of a larger nationwide strategy to build progressive energy at the local level following national losses in recent years.

“There’s been a push in the progressive movement to elect more progressive mayors and you’ve seen that in Chicago, Boston, and Helen’s such a clear part of that movement,” said Bill Neidhardt, a former staffer for Sanders’ 2020 presidential campaign who also worked on the campaign that elected Brandon Johnson mayor of Chicago.

In Philadelphia’s narrowly divided mayoral race, the support could boost turnout for Gym among young and progressive voters — which could be significant in a race that’s likely to be close. But the endorsements are more likely to rev up her existing base than expand it.

Sanders’ backing Wednesday followed a string of endorsements from U.S. Reps. Alexandria Ocasio-Cortez (D., N.Y.), Ayanna Pressley (D., Mass.), Jamaal Bowman (D., N.Y.), and Greg Casar (D., Texas), and Boston Mayor Michelle Wu.

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Several of the lawmakers have weighed in on other local elections, including Sanders, who also endorsed Sara Inamorato in the Allegheny County executive race this week. For the progressive movement, local endorsements are a way to build power and policy influence at a local level, as well as deepen their bench of elected leaders.

“These endorsements are a testament to [Gym’s] decades of work to create systems that work for the people,” Gym’s campaign spokesperson Maggie Hart said. “And these strong national networks will be essential to securing funding opportunities and leveraging support for our communities when she is mayor of Philadelphia.”

How much of an effect out-of-state political endorsements will have in a race crowded with as many as five front-runners is unclear.

“Helen was and remains the unified choice for self-described progressives and those endorsements are to be expected,” said strategist Mustafa Rashed, who is uninvolved with any of the campaigns. “I don’t know if they translate to more votes.”

And there could be a downside, Rashed said, if the endorsements are perceived as “outsiders ... who don’t understand the uniqueness of the challenges our city faces right now.”

One of Gym’s challengers voiced as much, following the Sanders’ endorsement.

“I’m not focused on national endorsements or making Philadelphia a laboratory for a national policy agenda,” Allan Domb tweeted. “Philadelphia needs more solutions, not more national politics.”

Another candidate, Cherelle Parker, has knocked Gym’s campaign because grassroots progressive organizers from New York plan to knock on doors in Philadelphia on its behalf. Parker’s campaign said in an email to supporters that out-of-towners were coming to “OUR neighborhood to try to sway the election.”

Philadelphia’s two congressmen, Brendan Boyle and Dwight Evans, have both backed Parker in the race. Boyle had joined Sanders and national Democrats in endorsing Johnson in the Chicago mayoral contest.

That race, a runoff between two candidates with contrasting ideologies, was much different from Philadelphia’s, which has five viable candidates, some who appeal to the same voters. But if the race comes down to a slim margin, momentum and a strong grassroots operation could be a difference-maker.

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Gym is endorsed by several progressive groups with robust organizing power, including Our Revolution, the Working Families Party, and the Progressive Change Campaign Committee, which has 11,000 members in Philadelphia and announced its endorsement of Gym on Wednesday.

“There could be a margin of victory based on who went out there and talked to more voters,” said Neidhardt, the former Sanders staffer. “And if that’s the case, if Bernie and [Ocasio-Cortez] end up energizing the youth vote in Philadelphia, I don’t think people should roll their eyes at that.”

Save for Gym’s progressive national allies, Philadelphia’s race has not attracted much national attention. That could change in coming weeks as observers look to see which direction the city takes. But some political strategists caution against reading too much into what Philadelphia’s election says about progressive energy nationwide.

“I think it’s gonna be very hard to extrapolate too much from the results because of Philadelphia’s weird and parochial electoral system,” political strategist J.J. Balaban said. “It’s looking plausible like the winner will get less than 30% of the vote, which just makes it kind of iffy to read into the mood of the electorate when you’re talking about such a small percentage of the electorate.”