Mayor of Philadelphia's Kensington plan is part of a broader shift on crime and drug policy in blue cities

Others push back. The city's jail system is already facing a crisis of understaffing, and every part of the city's criminal justice system has been working on a nearly decade-long project to reduce the prison population.

Mike Lee, the executive director of the ACLU of Pennsylvania and former chief of staff to District Attorney Larry Krasner, said the city and state have made significant progress on "acknowledging the harms" of arrests and convictions for low-level crimes. He pointed to the state's repeated expansion of its "Clean Slate Law," which allows for removal of some records for nonviolent crimes from public view.

"It's a conflicting signal to say there's a long-term harm with this conviction, but the short-term benefit is to you," Lee said.

He added: "One of the gains we've made is taking the stigma away from substance use and addiction. I'm very concerned and want to make sure the stigma of substance use doesn't go backward."

Liz Chiarello, an associate professor at St. Louis University who has studied medical sociology and the opioid crisis, agreed, saying the country has made strides in its language use around addiction and political leaders today more often describe it as a disease, not a choice.

But Chiarello said that even Democrats "have never been as progressive as people who advocate for people who use drugs would like them to be." She said policy shifts such as reducing funding to syringe exchange services or arresting people in addiction stand to reverse progress more.

"What all of our cities need to do is build on the harm reduction resources that exist," she said, "instead of taking them away and putting punishment in their place."

Inquirer staff writers Max Marin, Aubrey Whelan, Samantha Melamed, and Ellie Rushing contributed to this article.