Harris was responding to remarks Biden made a day earlier. He reportedly told an audience in New Hampshire that the 1994 bill "did not create mass incarceration." 

Republicans are already focused on Biden's record on criminal justice in national and state campaigns. "[W]e're going to crucify Biden for the 1994 crime bill," said Richard Holt, a GOP political consultant with Sirius Campaigns and member of the Project 21 black leadership network, adding the act "turned America into the prison capital of the world."

Republicans and the Trump campaign are looking to attract more support from minorities in 2020 and see an opportunity to draw those voters away from Biden, who is leading the Democratic field in support from black voters. Trump's support among black voters was 12% in March, a relatively small fraction but four points higher than the 8% who voted for him in 2016.

"Since Biden was such an outspoken supporter of locking up minorities, we'll go after him pretty hard," said Holt, who is advising two congressional campaigns in Ohio. "We'll be putting resources to help the black community understand the devastating effect of left-wing policies."

WHAT WAS IN THE 1994 CRIME BILL?

The crime bill, formally known as the Violent Crime Control Act and Law Enforcement Act, is often regarded as a leading contributor to America's massive prison population. It was written and sponsored in the Senate by then-Judiciary Committee chairman Joe Biden.

Most notably, the crime bill gave states and localities a financial incentive to build more prisons and impose longer sentences. The federal government offered billions in law enforcement grants to states that passed truth-in-sentencing laws, that ensured individuals served at least 85% of their sentence behind bars. The grants also helped put more police officers on the streets.

"The crime bill did not cause mass incarceration," explained Lauren-Brooke Eisen, a senior fellow at the Brennan Center for Justice. "But the bill certainly played a role in providing funding to states to increase prison time of individuals convicted of nonviolent crimes and under this grant program states got the message to expand prison capacity."

The 1994 bill continued a decadeslong trend of imposing harsh penalties for drug crimes, including minimum mandatory sentences. It enacted the "three strikes" rule to impose a mandatory minimum life sentence for certain habitual offenders and authorized the death penalty for dozens of new federal crimes. Despite evidence at the time suggesting access to education helped reduce recidivism rates, the Congress and Clinton administration banned federal and state inmates from receiving Pell Grants. 

BIDEN HASN'T ACKNOWLEDGED THE NEGATIVE EFFECTS

Other politicians have apologized for their role in crafting policies that led to roughly 2.2 million Americans behind bars. During Hillary Clinton's presidential campaign, former President Bill Clinton acknowledged, "I signed a bill that made the problem worse. And I want to admit that."

That Biden has yet to apologize is causing some discomfort among advocates of criminal justice reform.

"Biden's involvement in the Crime Control Act was more than the average lawmaker at the time. He was chair of the Judiciary Committee. He was instrumental in having that bill passed," explained Alex Friedmann, the associate director of the Human Rights Defense Center and managing editor of Prison Legal News. "But Biden has never acknowledged the role that he had in a bill that perpetuated mass incarceration and increased the number of people going to prison, particularly minorities."

Biden defended his vote last month at a rally in New Hampshire earlier this month telling the crowd about how the crime bill helped him "beat" the National Rifle Association (NRA).

"I'm the only guy ever nationally to beat the NRA," Biden argued. "Everybody talks about the bad things. Let me tell you about the good thing in the crime bill." While carefully avoiding the harsh sentencing laws, Biden explained that the law enacted an assault weapons ban (that expired in 2004), a ban on high-capacity magazines and it introduced background checks.

Biden also argued that he fought for $10 billion in crime prevention funding that was included in the crime bill as well as drug courts to get drug users into treatment rather than prison.

Biden has admitted he regrets supporting the Anti-Drug Abuse Act of 1988, which included a provision to punish crack cocaine offenses more severely than powder cocaine.

At a Martin Luther King Jr. breakfast in January Biden said "it was a big mistake" to punish the two drugs differently, adding, "It's not different. But it's trapped an entire generation."

Biden contrasted his mistake with the work he did with the Obama administration to pass the 2010 Fair Sentencing Act, which reduced the sentencing disparity between crack and powder cocaine from 100:1 to 17:1.

On his official campaign page, Biden's argument for criminal justice reform is slim on details. The former vice president advocates changes that "prioritize prevention, eliminate racial disparities at every stage, get rid of sentencing practices that don’t fit the crime, and help make sure formerly incarcerated individuals who have served their sentences are able to fully participate in our democracy and economy."

One other 2020 presidential candidate voted for the Violent Crime Control Act and Law Enforcement Act. Vermont Independent Sen. Bernie Sanders explained he voted in favor of the bill because it contained the assault weapons ban and the Violence Against Women Act.

POLICY SHIFT FROM INCARCERATION TO REHABILITATION

Jesse Lee, a spokesman for the Center for American Progress Action Fund noted that the American public and its representatives have evolved considerably since the early 1990s when the crime bill passed issues of crime and punishment. In 1994, the crime bill had broad bipartisan support at the time and was ushered into law by Democratic President Bill Clinton.

"The 1994 bill was meant to send a message that there would be no tolerance for drug dealing and to some extent drug use. It was kind of a desperate reaction to a chronic problem," he said. Crime rates in the U.S. peaked in 1991. Murder and violent crimes were occurring at more than twice the current rates. The public was also battling an epidemic of crack addiction.

The policies enacted in the 1990s and earlier hadn't been tested for their effects. "Now that we have seen the evidence and seen the results...there's no way to look at how things turned out and say it has not had enormous unintended negative consequences," he said.

Many critics were quick to point out the inconsistency of Trump's attack on Biden considering the president was a vocal advocate of the same "tough on crime" attitude that helped usher in the bipartisan crime bill. In 1989, as a private citizen, Trump took out a full-page advertisement in all four New York City newspapers calling for the death penalty for five black and Hispanic teens who were charged with assaulting and raping a jogger in Central Park. All of the accused had their convictions overturned in 2002 with DNA evidence supporting their innocence.

In 2018, with the pendulum swinging toward rehabilitation rather than incarceration, Trump and a bipartisan group of lawmakers successfully passed criminal justice reform. The First Step Act started to "fix" some of the negative effects of the 1994 bill, as the president tweeted. Many supporters have emphasized the bill is exactly what its name suggests, only a first step. 

The bill shortened mandatory minimum sentences for nonviolent drug offenses and eased the "three strikes" rule for certain offenders. Trump also pledged more than $500 million to fund a variety of educational and job training programs proven to help reduce recidivism, including allowing a limited number of Pell Grants to help inmates access higher education.

The Trump bill only applied to individuals in the Federal Bureau of Prisons, about 181,000 of the total 2.2 million-person prison population. Activists are also concerned that the president's budget does not fully fund the programs authorized under the First Step Act.

Ultimately, both political parties helped craft what many consider a broken U.S. criminal justice system over decades, with the 1994 crime bill, the 1988 Anti-Drug Abuse Act and other laws going back to the 1968 Safe Streets Act.

Americans are still living with the long-term effects of those policies today, Friedmann said. "Whichever of the numerous candidates eventually gets into office will also enact laws and policies that will have a significant long-term impact on our justice system and, therefore, our country as a whole. So people need to consider that regardless of who they vote for."