On a muggy August afternoon nearly five years ago, criminal justice professor Wesley Bell saw protesters march past his front porch in Ferguson, Missouri.

The killing of Michael Brown, an unarmed black teenager, by the white police officer Darren Wilson set off protests in the black-majority city over police brutality and long simmering tensions around racial inequality. The unrest transfixed a nation and propelled the Black Lives Matter movement into the political mainstream.

Bell joined the demonstrations demanding justice for Brown.

The experience was formative for Bell’s political aspirations. In April 2015, he won a seat on the Ferguson city council. Then, last August, he shocked the state’s Democratic political establishment by roundly defeating a seven-term incumbent to become prosecuting attorney for St Louis county.

The protester was now the prosecutor. And Bell had won on a radical platform promising to end mass incarceration, dramatically reform the cash bail system, end the death penalty and decriminalize marijuana possession in the county of just under a million people.

Bell is part of a movement. Across the country, progressives have won office in district attorney and prosecutor races. They have claimed victories in major cities like Philadelphia and Chicago but also in places like Portsmouth, Virginia, where in February 2015, Stephanie Morales, 31, became the city’s first ever woman elected to the office of commonwealth’s attorney. Pending a recount in the Queens DA race, the democratic socialist Tiffany Cabán could become the latest.

These candidates have bucked a decades-long “tough-on-crime” trend adopted by both major parties, in favor of fundamental reforms to criminal justice. They have been aided by armies of volunteers through traditional door-to-door campaigning, digital organizing, and – in some cases – funding from the billionaire George Soros and national progressive groups.

The Guardian interviewed more than half a dozen of these office-holders to take the pulse of a movement gaining steam, even as Donald Trump has appointed and confirmed more than 100 conservative federal judges. In the Trump era, this struggle over who will define the future of the American criminal justice system may endure long after the president exits the White House.

Wesley Bell in 2015. Within his first 100 days as prosecuting attorney for St Louis county his office had reduced the county’s jail population by 12%, taking it to its lowest level since 2002. Photograph: Sid Hastings/EPA

The new Democrats often act quickly. Bell, for example, fired the veteran St Louis county prosecutor who had presented grand jury evidence in the Michael Brown case (a grand jury declined to bring charges against Wilson). Within his first 100 days, his office said it had reduced the county’s jail population by 12%, taking it to its lowest level since 2002. And, within his first six months, Bell established an independent unit to tackle wrongful convictions and abuse by police.

“As progressive prosecutors, we have the opportunity to lead the way in reducing mass incarceration,” said Bell.

And more like Bell are emerging in every part of the country, says Chris Lazare, organizing director for the Real Justice Pac, an organization that consults and endorses candidates running for these offices, so often held by white men.

“A lot of black and brown lawyers are stepping up,” said Lazare.

‘We are in the fight’

Philadelphia’s district attorney, Larry Krasner, tends to ramble off at tangents. He can jump from discussing Michelle Alexander’s The New Jim Crow to the legislative minutiae of ending cash bail, often in the same breath. He likens mass incarceration to a “gulag”. He is also the most powerful law enforcement official in the nation’s sixth largest city.

Krasner won a shock victory in the May 2017 Democratic primary. As arguably the most high-profile progressive district attorney in the country, Krasner is a darling for social justice activists and a hated villain for his powerful enemies. They include the city’s police union, the Republican-controlled Pennsylvania legislature and the Democrat attorney general, Josh Shapiro.

The Philadelphia district attorney, Larry Krasner, is a darling for social justice activists and a hated villain for his powerful enemies. Photograph: Matt Rourke/AP

“We’ve accomplished enough so the institutions woke up,” Krasner said, listing accomplishments like reducing the city’s jail population, ending cash bail for low-level crimes and exonerating eight individuals facing life sentences through an accountability unit he created. “This is what happens when you have moments for social change and they start to change. There’s a commotion.”

The resistance to Krasner’s policies reached a peak last month when the state legislature passed a law, known as Act 58, giving authority to Shapiro to prosecute certain firearms violations in Philadelphia – and nowhere else in the state. The effort to wrest power from Krasner was “an attack on democracy” Krasner said. Shapiro backed down.

The episode, Krasner said, was indicative of this cultural moment. “If you look at it as a movement, we are past the laughing, we are past the ignoring,” said Krasner. “We are in the fight. The only step left is winning.”

Sustaining a movement

It was the 1994 Crime Bill that truly altered the nation’s criminal justice system. It established the infamous “three strikes” mandatory life sentence policy for repeat offenders, allocated money to hire 100,000 new police officers and granted nearly $10bn for new prisons.

The nation’s prison population soared, devastating communities of color in every city in America, said Rachael Rollins, the district attorney for Suffolk county in Massachusetts, which includes Boston.

Rollins says she knows firsthand the impact of these policies. Two of her siblings are incarcerated.

“My life experience is a little different from traditional DAs,” she said.

Rollins won a five-way race last September in a competitive primary that laid bare party divisions. She assembled a broad coalition across gender, racial and class lines, particularly in Boston’s working-class neighborhoods, to beat her leading opponent, Greg Henning, an assistant district attorney backed by Boston’s political class.

Rollins pledged to not prosecute minor crimes like trespassing, shoplifting and drug possession and to increase efforts to decriminalize poverty, addiction and mental illness through newly created diversionary programs.

On her first day in office, Rollins issued a memo that included a “do not prosecute list” of 15 types of offenses for the 300 prosecutors she inherited. The resistance from the city’s law enforcement institutions and its statehouse allies was fierce.

The National Police Association accused Rollins of “reckless disregard” for Massachusetts law in a written complaint to the state’s bar association. Then came a letter from a member of the Republican governor Charlie Baker’s cabinet condemning her memo.

Rollins continued to push through her agenda, despite the blowback. Last month, her office won a preliminary injunction against US Immigrations and Custom Enforcement (Ice) blocking immigration arrests at state courthouses.

She has, though, come under criticism from advocates. In March, CourtWatch MA, an oversight group, found many of the crimes from Rollins’ “do not prosecute list” were still being prosecuted within her first 100 days in office, but just in different ways. Rollins acknowledged the process had been slow.

The criticism highlighted the political reality for insurgent candidates elected to office on promises to undo policies crafted over decades. Three years ago, Kim Ogg became the first Democrat elected district attorney in Harris county – which includes Houston – in nearly 40 years on a progressive platform. Heading into her 2020 re-election campaign, she faces a challenger from her left – democratic socialist Audia Jones – who says she has failed to fulfill her promises.

The stakes are high for the movement because voters newly interested in these races expect results quickly, said David Alan Sklansky, a Stanford law professor who studies district attorneys.

Falling crime rates in a number of urban areas in recent years have been important in making this movement politically possible, Sklansky added.

Still, the movement itself – despite the resistance it has faced in nearly every place where a progressive has won office – is ultimately a response to the will of voters who want to see reform, said Marisa Maleck, a lawyer and conservative legal commentator who clerked for the supreme court justice Clarence Thomas in 2015.

“The tough-on-crime approach works to put people away,” said Maleck, who identifies as Libertarian. “But, in these races, voters clearly are saying that’s not working.”

Future for movement?

Since before Trump was elected, conservative organizations in Washington, like the Judicial Crisis Network and the Federalist Society, have methodically guided the president to their preferred judicial picks to both federal courts and to the supreme court.

The moves have demoralized Democratic voters who see the long-lasting consequences of these choices. Republican-led state houses have pushed through a slew of anti-abortion laws emboldened by the right’s hold on the nation’s top court.

The battlefield for progressives has, thus, shifted from the Supreme court to the prosecutor’s office.

“Our supreme court is gone as an agent of good in seeking justice,” said Krasner, who argues that winning more and more prosecutor’s offices is critical to long-lasting reform.

The progressive prosecutor movement is still in its nascent phase, Krasner and others interviewed agreed. But Sklansky, the Stanford law professor, still counts this era as historic.

“I can’t think of another moment where there was as broad a movement nationwide to moderate criminal justice policies,” he said. “The fact that dystopian rhetoric from its opponents hasn’t stalled this movement is some sign that it’s durable.”