When Sen. Amy Klobuchar launched her campaign for president on Sunday, the Minnesota Democrat did something she has done often in her two-decade career in politics—invoked her past as a criminal prosecutor.

Klobuchar’s experience as the top law enforcer for Minnesota’s most populous county has long been a sterling credential for her in politics. It burnished her image as a no-nonsense public servant who cracked down on crime, guns, and child and elder abuse after being elected to clean up a place with the notorious nickname “Murderapolis.”

In her eight-year term, from 1999 to 2007, Klobuchar embraced a “tough on crime” approach that was widely practiced by law enforcement at the time. She put drug offenders behind bars more frequently and for longer stretches, sharply increased the prosecution of repeat offenders, and launched campaigns against graffiti and vandalism.

But what were seen as the best practices of prosecutors in the 1990s and 2000s have not aged well. The public increasingly views them as having contributed to mass incarceration and worsened race and class disparities in the justice system. As she runs for president, Klobuchar will confront something new: criticism and anger, on a national level, over her work as a prosecutor.

Possible rivals for the Democratic nomination who also backed the tough-on-crime line have already braced for backlash from the party’s progressive base. Sen. Kamala Harris (D-CA), formerly the attorney general of California, has branded herself as a reformer and recast her background as one of a “progressive prosecutor.” Joe Biden, who led the charge to pass hard-line crime laws as an influential senator, admitted in January that he “hasn’t always been right” on criminal justice.

Klobuchar has faced less scrutiny, and she has not tried to publicly rebrand her record in the way her Senate colleague Harris has.

Those familiar with Klobuchar’s time as Hennepin County attorney recall a prosecutor who was strategic, organized, and competent. Crime decreased in the county during her tenure, earning her plaudits from newspaper editorial boards and the federal government. She went after a respected judge for fraud, putting him behind bars, and brought sexual assault charges against Kirby Puckett, one of the state’s biggest sports stars.

But some believe that Klobuchar was not sensitive to the effects of her policies on minority communities. David Schultz, a law professor at Mitchell Hamline School of Law in Saint Paul, studied law enforcement and race issues while Klobuchar was county attorney.

“People are going to say she did a great job, but I do think she had a blind side to racial disparity types of issues,” Schultz said. “There’s nothing to indicate to me that when Klobuchar was in office, she particularly was paying attention to these issues of racial disparities.”

“ People are going to say she did a great job, but I do think she had a blind side to racial disparity types of issues. ” — David Schultz, law professor

News of Klobuchar’s impending campaign launch sparked recollections on social media of the damaging impact her approach had in places like Minneapolis’ North Side, the traditional heart of the city’s black community.

A longtime criminal justice advocate, who did not wish to criticize Klobuchar on the record, said that “being a tough-on-crime prosecutor who has failed to evolve and take a leadership role [on criminal justice reform] is going to damage her… I don’t understand how Sen. Klobuchar is going to just skate past this.”

A spokesman for Klobuchar noted that during her time as county attorney, the rate at which African-Americans and other minorities were sent to jail—a destination for those serving shorter sentences for lower-level offenses—declined significantly in Hennepin County. He pointed to her “community prosecution model” that assigned prosecutors to work with people in their neighborhoods to reduce crime.

But as Klobuchar worked to secure longer sentences for crimes which sent offenders to prisons, not jails, the county’s overall prison population grew. The African-American prison population grew during her time in office, but not at a disproportionate rate.

Criminal justice experts caution that many factors can influence data about incarceration. Other data points support critics’ objections to Klobuchar’s policies. A study commissioned by her attorney’s office found that black youth made up a disproportionate share of the population of Hennepin County’s juvenile detention facility from 2002 to 2004.

In general, Klobuchar cracked down on crime as aggressively as any urban prosecutor did during this era, experts say. In her first year on the job, Klobuchar doubled the rate at which drug dealers were sent to prison, and successfully prosecuted nine times as many “career offenders” as her predecessor did the year before.

She prosecuted more crimes as felonies, bringing the first felony charge for failure to pay child support that the county had seen in 30 years. A task force she set up to combat graffiti and other “livability” related crimes led to over 30 people, mostly minors, being charged with felonies, which typically carry multi-year prison sentences.

In cases related to elder abuse, which Klobuchar created a task force to tackle, she sought lengthy sentences for offenders, sending one man to prison for eight and a half years for breaking into the apartment of an 82-year-old woman and stealing her car.

In 2001, she was a leading supporter of a bill at the Minnesota state legislature to make drunk driving a felony offense. It became law; a Minneapolis Star Tribune analysis found that no criminal justice policy change since 1992 had done more to grow the state’s prison population, which increased by 150 percent from that year to 2016.

Liberal lawmakers in Minnesota grew increasingly worried that law enforcement officials like Klobuchar were too focused on prosecuting drug crimes. In 1990, drug offenders made up 9 percent of the state prison population; by 2004, it was 23 percent.

“ We must keep a focus on drug dealers. ” — Amy Klobuchar in 2004

Keith Ellison, who was then a state legislator and is now Minnesota attorney general, promoted a bill to relax the state’s strict standards for sentencing on drug offenses, arguing that prison cells should be reserved for “the truly dangerous.” Klobuchar was wary of the effort: “We must keep a focus on drug dealers,” she told the Star Tribune in 2004.

Her approach earned Klobuchar the admiration even of her political enemies: the conservative Power Line blog called her “the best Hennepin County Attorney of the past 30 years,” praising her for “vigorously [supporting] the prosecution and incarceration of the gangbangers without the slightest public display of hesitation, handwringing, or apology.”

In recent years, Klobuchar has pushed for reforms to the criminal justice system. The senator was a co-sponsor of the First STEP Act, the bipartisan criminal justice bill that was signed into law last year. In a December speech, she hailed in particular the bill’s provisions to secure more lenient treatment to low-level drug offenders. In her Sunday speech, she vowed to keep advocating for reform.

Klobuchar has also acknowledged that old approaches to criminal justice were problematic. “We know that there is racism in the system that needs to be fixed,” she said on Meet the Press in August 2018.

Lara Bazelon, a law professor at the University of San Francisco who criticized Harris’ record on criminal justice in a New York Times op-ed, said Klobuchar’s recognition of racism in the system simply states the obvious.

“It’s not an answer that’s going to satisfy me or satisfy anybody that believes in true criminal justice reform,” Bazelon said, “and there’s a lot of us.”