San Francisco residents have voted to recall the district attorney, Chesa Boudin, who was elected on an agenda of criminal justice reform but faced intensifying backlash from law enforcement, conservatives and residents concerned about crime.

Boudin’s removal as the city’s top prosecutor in the middle of his first term is a major blow to a growing movement across the US to elect progressive DAs dedicated to tackling mass incarceration, police brutality and racism in the legal system.

The race was called by the Associated Press just over an hour after polls closed, with partial returns showing the recall received about 60% of the vote.

In a speech to his supporters on Tuesday night, Boudin struck a defiant yet optimistic tone, saying he had been outspent by opponents but noting progressive candidates were winning or leading in their races in other parts of California and the US: “The movement that got us elected in 2019 is alive and well. We see the results from coast to coast, from north to south.”

He noted that even as his office reduced incarceration rates and prioritized mental health and drug treatment, “crime rates stayed flat or declined”, adding: “We’ve already won, because we are part of a national movement that recognizes we can never incarcerate our way out of poverty. We have shown San Francisco and the world that we do not need to rely on fearmongering or exploitation of tragedy to build safety.”

Boudin is a former public defender and the son of two leftist Weather Underground activists who spent decades in prison. He became one of the most prominent prosecutors in the US fighting to undo the damage of harsh punishments in a country that locks up more people per capita than any other.

After his election in 2019, Boudin created a wrongful conviction unit that freed a man imprisoned for decades; eliminated cash bail in an effort to ensure people weren’t jailed because they were too poor to pay a fee; stopped prosecuting contraband cases that originated with minor traffic stops; and became the first San Francisco DA to charge an officer for an alleged on-duty manslaughter.

Through resentencing, diversion and other reforms, Boudin has overseen a 35% reduction in the population of San Francisco residents in state prisons, a 37% decline in the adult jail population, and a 57% decline in the juvenile jail population.

Boudin’s ousting came on a day of high-stakes primary races up and down the state, with the rising cost of living, policing and the state’s growing homelessness crisis high on voters’ minds.

In Los Angeles, a mayor’s race that pitted a tough-on-crime real estate developer, Rick Caruso, against the former community organizer and Democratic congresswoman Karen Bass will head for a November runoff after neither candidate cleared the necessary 50% vote threshold to win outright. That election was marked by record spending and a focus on crime and homelessness. Caruso, who has an estimated net worth of $4bn, poured more than $38m of his own fortune into his campaign, with a pledge to “clean up” Los Angeles.

Meanwhile, the state’s governor, Gavin Newsom, cruised to an easy victory, advancing to the November general election, where he will be an overwhelming favorite to win a second term barely a year after surviving his own recall attempt.

The state’s attorney general, Rob Bonta, a progressive who has backed reform efforts, advanced to the general election on Tuesday night, with early results showing Bonta held a substantial lead over three challengers with more conservative platforms.

Tuesday’s primary has been marked by low turnout, in what experts say is a stark sign of political apathy considering all registered voters in California were mailed a ballot.

“Even if you make it extremely easy to vote, like in California, but the political culture, candidates and issues aren’t there, you aren’t going to increase the turnout,” the political scientist Fernando Guerra said.

The San Francisco recall campaign had a huge financial advantage, backed by ultra-wealthy donors, the San Francisco Chronicle reported, including Ron Conway, an early DoorDash investor, and William Oberndorf, a billionaire and Republican mega-donor. Critics blamed Boudin for crime, violence, homelessness, retail thefts and other challenges that escalated during the pandemic. Homicides have increased in the city, echoing national trends, but overall violent crime decreased during the pandemic.

Experts say prosecutors’ policies often have little bearing on crime rates, which are a function of complex socioeconomic factors, with some research suggesting that harsher punishments do not deter crime. As the recall gained ground, Boudin’s office noted that some California regions with “tough on crime” DAs promoting a traditional punitive approach were experiencing higher crime rates than San Francisco.

In an interview before the election, Boudin said the recall was “dangerous for democracy”, noting that voters were opting to remove him without knowing who would replace him. The recall, he said, was relying on a “Republican- and police union-led playbook to undermine and attack progressive prosecutors who have been winning elections across the country”.

San Francisco’s mayor, London Breed, a moderate Democrat, will appoint a successor to take over the DA’s office, but did not immediately announce her pick on Tuesday. Breed has increasingly opposed Boudin’s policies and criminal justice reforms more broadly, repeatedly siding with police officials in disputes and pushing to expand the police force and its powers. Boudin will be removed 10 days after the results are formally adopted, and his replacement will remain in place until the November election.

Progressive DAs in Philadelphia and Chicago have won re-election despite intense backlash but have also faced renewed calls to have them removed from office. There are also efforts to recall the Los Angeles DA, who was elected on a reform platform, but an initial campaign last year failed to get enough signatures.

Miriam Krinsky, the executive director of Fair and Just Prosecution, a network of local prosecutors who support reform, said in a statement on Tuesday night that Boudin’s ouster was the result of “a low turnout recall process easily swayed by special interests and coming at a time of deep frustration and trauma”. She said there was no evidence that reform-minded prosecutors had caused an uptick in crime in the US and praised Boudin for creating diversion programs to reduce recidivism.

Recall efforts, often backed by conservatives, have become increasingly common in California, where voters can petition to remove a politician for any reason. In February, San Francisco held its first recall vote in the city since 1983, with residents electing to remove three school board members amid frustrations about closed schools during the pandemic.

The Associated Press and Lois Beckett contributed reporting