Four years ago, progressive prosecutors were in the sweet spot of Democratic politics. Aligned with the growing Black Lives Matter movement but pragmatic enough to draw establishment support, they racked up wins in cities across the country.

Today, a political backlash is brewing. With violent crime rates rising in some cities and elections looming, their attempts to roll back the tough-on-crime policies of the 1990s are increasingly under attack — from familiar critics on the right, but also from onetime allies within the Democratic Party.

In San Francisco, District Attorney Chesa Boudin is facing a recall vote in June, stoked by criticism from the city’s Democratic mayor. In Los Angeles, the county district attorney, George Gascón, is trying to fend off a recall effort as some elected officials complain about new guidelines eliminating the death penalty and the prosecution of juveniles as adults. Manhattan’s new district attorney, Alvin Bragg, quickly ran afoul of the new Democratic mayor, Eric Adams, and his new police commissioner over policies that critics branded too lenient.

The combative resistance is a harsh turn for a group of leaders whom progressives hailed as an electoral success story. Rising homicide and violent crime rates have even Democrats in liberal cities calling for more law enforcement, not less — forcing prosecutors to defend their policies against their own allies. And traditional boosters on the left aren’t rushing to their aid, with some saying they’ve soured on the officials they once backed.

“I think that whole honeymoon period lasts about five or six hours,” said Wesley Bell, the prosecuting attorney for St. Louis County in Missouri, who is seeking re-election this fall.

Mr. Bell, a former city councilman in Ferguson, Mo., is part of the group of prosecutors elected on a promise to address racial disparities in the criminal justice system. Most support eliminating the death penalty and cash bail, limiting prosecutions for low-level, nonviolent offenses and scaling back sentences.

In a show of political strength, progressive prosecutors in Chicago and Philadelphia handily defeated challengers in recent years. Mr. Bell’s re-election bid in November is one of several races being watched for signs that voters’ views have shifted on those policies as violent crime has risen and racial justice protests have fallen out of the headlines.

Homicide rates spiked in 2020 and continued to rise last year, albeit less slowly, hitting levels not seen since the 1990s. Other violent crimes also are up. Both increases are occurring nationally, in cities with progressive prosecutors and in cities without.

That’s left no clear evidence linking progressive policies to these trends, but critics have been quick to make the connection, suggesting that prosecutors have let offenders walk and created an expectation that low-level offenses won’t be charged. Those arguments have landed on voters and city leaders already grappling with a scourge of pandemic-related ills — including mental health care needs and housing shortages, rising drug use, even traffic deaths.

Last week, a Quinnipiac University poll of registered voters in New York City found that 74 percent of respondents considered crime a “very serious” problem — the largest share since the survey began asking the question in 1999 and more than 20 percentage points greater than the previous high, which was recorded in January 2016.

Politicians are heeding those concerns. In New York, Mr. Adams, a Democrat, has promised to crack down on crime, and his police commissioner, Keechant Sewell, slammed Mr. Bragg’s proposals as threatening the safety of police officers and the public. In San Francisco, Mayor London Breed has become an outspoken critic of Mr. Boudin’s approach, which emphasizes social services over policing.

“This is not working,” Ms. Breed said recently on The New York Times podcast “Sway.” “We’ve added all these additional resources — the street crisis response team, the ambassadors, the services, the buildings we purchase, the hotels we purchase, the resources. We’ve added all these things to deal with food insecurity. All these things. Yet people are still being physically harmed and killed.”

The criticisms from two prominent Black mayors are particularly biting. In their liberal cities, the leaders’ nuanced complaints have far more influence with voters than familiar attacks from Republicans or police unions. Both mayors have argued that the minority communities that want racism rooted from the justice system also want more robust policing and prosecutions.

President Biden, who was one of the architects of the tough-on-crime criminal justice overhaul of the 1990s, recently spoke highly of Mr. Adams’s focus on crime prevention. Some prosecutors and their allies took that as sign that the Democratic establishment is digging in on a centrist approach to criminal justice reform.

Mr. Biden’s comments came as the Democratic Party worried about retaining the support of moderate suburban voters in midterm elections this year. Many Democratic lawmakers and strategists believe that protest slogans like “defund the police” hurt the party in the 2020 elections — particularly in Congressional swing districts and in Senate races. Republican candidates, eager to retake control of Congress in November, already have run advertisements casting Democrats as soft on crime.

Most progressive prosecutors oppose the calls to gut police department budgets, but that is a nuance often missed. At one liberal philanthropic group, some newer givers have said they will not donate to any criminal justice groups — or to the campaigns of progressive prosecutors — because they don’t want to endorse defunding the police, according to a person who connects donors to criminal justice causes, and who insisted on anonymity to discuss private conversations.

Samuel Sinyangwe, an activist who has been involved in several organizations pushing progressive prosecutors, said prosecutors hadn’t been as forceful as law enforcement unions in selling their solutions to rising violence in cities.

“Police are spending a lot of money convincing people the appropriate response to that is more policing and incarceration,” he said. “I think that individual cities and counties are having to push back against that narrative. But I think they’re struggling to do that right now.”

In San Francisco, Mr. Boudin argued that the effort to recall him was fueled by politics, not voters’ worries about crime. He pointed to the Republican megadonors who have funded the recall efforts and said Ms. Breed has a political incentive to see him ousted — he beat her preferred candidate for district attorney.

“These are Republican talking points,” Mr. Boudin said. “And it’s tremendously destructive to the Democratic Party and the long-term progress that the party is making at the local and national level around public safety and criminal justice to allow a few folks dissatisfied with a local election to undermine that progress.”

Mary Jung, a Democratic activist leading the recall campaign, said those who painted the efforts as fueled by conservatives or moderates were missing the point. Many of their supporters, she said, are lifelong liberal Democrats.

Those voters, she said, don’t view the effort to recall Mr. Boudin, who was elected in 2019, as a broad shift away from progressive policies, but as a local response in a community that feels unsafe. She cited several attacks against Asian immigrants and incidents of shoplifting as the sort of crimes that have rattled residents, regardless of political ideology.

In another sign of Democrats’ discontent, San Francisco voters ousted three progressive members of the Board of Education in a recall election driven by pandemic angst.

“Over 80,000 San Franciscans signed our petition and we only needed 53,000 signatures,” Ms. Jung said. “There’s only 33,000 registered Republicans in the city. So, you know, you do the math.”

Some progressives warn against ignoring people’s fears. Kim Foxx, the state’s attorney for Cook County, which includes Chicago and some of the country’s most violence-plagued communities, said that any dismissive rhetoric could make prosecutors risk looking out of touch.

“You can’t dismiss people,” Ms. Foxx said. “I live in Chicago, where we hit 800 murders last year, and that represents 800 immediate families and thousands of people who are impacted.”

Ms. Foxx faced a well-funded opponent and won re-election in 2020, as did Philadelphia’s district attorney, Larry Krasner, the following year. Those victories show the resilient support for progressive ideas, Mr. Krasner said, warning the Democratic Party not to abandon them.

“Put criminal justice reform on the ballot in every election in almost every jurisdiction, and what you’re going to see is a surge in turnout,” Mr. Krasner said. “And that turnout will overwhelmingly be unlikely voters, reluctant voters, brand-new voters, people who are not connected to what they see as governmental dysfunction between the parties — but they are connected to an issue that has affected their communities.”

But there are signs that attitudes about overhauling the criminal justice system are changing even among progressives. Many activists have shifted their focus away from electoral politics and toward policies they think address root of the problem, such as reducing the number of police and abolishing prisons.

That “makes it very difficult to even defend or support particular prosecutors, because at the end of the day, they’re still putting people in jail,” Mr. Sinyangwe said.

In 2020, Mr. Bell, the St. Louis prosecutor, faced the ire of the same progressive activists who had helped elect him. That July, he announced that his renewed investigation into the 2014 fatal police shooting of Michael Brown Jr., a young Black man, which ignited weeks of protests, had delivered the same results: no charges for the officer who killed him.

Mr. Brown’s mother denounced Mr. Bell’s investigation. Speaking to reporters then, Mr. Bell said the announcement was “one of the most difficult things I’ve had to do as an elected official.”

Asked to discuss the incident and the investigation, Mr. Bell declined.

Josie Duffy Rice, the former president of The Appeal, a news outlet focused on criminal justice, said that in some ways the voters were learning the limitations of the progressive prosecutor’s role.

“Prosecutors have the power to cause a lot of problems,” Ms. Duffy Rice said. “But not enough power to solve problems.”