Joe Biden carries into any presidential run the burden of his own history -- in particular, his complicity in crafting a generation of drug policies now synonymous with failure. The vice president's long record of advocating laws that helped fuel the drug war and mass incarceration could serve as an early stumbling block in a White House campaign.

In the 1980s and 1990s, then-Sen. Biden and other lawmakers enacted a wave of tough-on-crime measures, driven by record spikes in violent crime and a crack epidemic that was ravaging major cities and poor and minority communities across the nation. Those laws, backed by both Democrats and Republicans, would lead to millions of people behind bars or dead, give rise to increasingly militarized police forces, and funnel billions of dollars into a global war on drugs.

Now that legacy is under intense criticism. The 2016 election cycle has featured heated debate, especially among Democrats, about the historic injustices of the U.S. criminal justice system and the need for reform. A Biden presidential run may ultimately be determined by his ability to convince voters that he's evolved on drug policy over the last 30 years.

This won't be an easy task. Slate’s Jamelle Bouie last month described Biden as "the Democratic face of the drug war."

Biden gave a green light to policing for profit.

Biden's pursuit of the drug war began in 1984 with his cosponsorship of a law that created new incentives for police to seize assets of individuals suspected of, though not charged with, involvement in drug trafficking. The resulting expansion of so-called civil asset forfeiture was initially praised as law enforcement took yachts, mansions and other luxury items away from supposed drug dealers. But over time, police have regularly used the same process to target average citizens, even after reforms were passed in 2000.

Opponents argue that civil asset forfeiture violates the constitutional guarantee of due process and is used abusively, particularly against those who are financially disadvantaged. People who committed no crime have still lost their cars or their meager savings. Under the 1984 law, a significant portion of the forfeited assets goes back to the police departments that made the seizure. Critics call that policing for profit.

Biden helped create a huge disparity between crack and powder cocaine penalties.

Two years later, Biden authored portions of the Anti-Drug Abuse Act, which created a 100-to-1 sentencing disparity between crack and powder cocaine. Until reforms were made in 2010, individuals caught with just 5 grams of crack were subject to the same mandatory minimum sentence of five years in prison as those caught with 500 grams of powder cocaine. The higher penalties for crack fueled mass incarceration and disproportionately affected African-American communities.

He's also one of the fathers of the drug czar.

In 1988, Biden helped usher in harsher penalties for drug possession and create the Office of National Drug Control Policy, run by the "drug czar." The rhetoric of the first chief, William Bennett, recalled that of Harry Anslinger, the much-criticized first commissioner of the Federal Bureau of Narcotics, a precursor to the modern-day Drug Enforcement Administration.

Anslinger was the father of the war on marijuana and often used racial fears to gin up support for drug prohibition. For his part, Bennett once said he didn't have a problem with beheading drug dealers and was disappointed that those dealers, when arrested, could not be imprisoned indefinitely without trial. Bennett's hard line would define the drug czar's office for many years.

Even today, the office is legally barred from supporting the legalization of any Schedule I substance. But the current drug czar, Michael Botticelli, has moved away from its tough-on-crime roots toward a more health-focused approach, favoring treatment over incarceration.

Biden's name is on the 1994 crime law, for better and worse.

One of Biden's signature pieces of legislation -- and now perhaps his most controversial -- is the sweeping 1994 Violent Crime Control and Law Enforcement Act. It further expanded the drug war and the federal death penalty, leading to more severe sentences and a ballooning of the prison population. Two decades later, the portions of the bill that focused on aggressive incarceration as a way to lower crime rates are widely viewed as a terrible mistake.

Biden's own reflections on the legislation suggest he may agree with some of the criticism, though he and his supporters have made it clear that he's proud of other included measures, like the Violence Against Women Act, funds for drug prevention and treatment programs, and billions of dollars in grants to local and federal law enforcement. As Vox recently pointed out, however, those grants would feed some of the drug war's worst police priorities, disproportionately focusing resources on black neighborhoods and encouraging officers to rack up arrests in return for further funding.

His aggressive stance against Ecstasy set back harm reduction efforts.

In 2003, Biden built on his work from the previous two decades by sponsoring the Illicit Drug Anti-Proliferation Act, commonly known as the RAVE Act, the name of an earlier Biden-sponsored bill with many of the same measures. The new law targeted businesses that knowingly provided space for raves, where illicit substances -- particularly MDMA, aka Ecstasy -- were frequently used.

Critics of the law say it has simply scared business owners away from providing common sense services to reduce medical emergencies for fear of federal prosecution. Harm reduction measures, like offering on-site monitoring and medical care to attendees who take drugs or offering drug checking kits to ensure users don't consume tainted substances, have been largely discouraged by the law. In the past, authorities were also encouraged to consider the sale of innocuous items like glow sticks or pacifiers at these venues as potential signs of support for drug use.

Biden has been a chief proponent of the global war on drugs.

The vice president has come under fire in recent years for supporting a foreign policy that still prioritizes aid for drug prohibition and aggressive interdiction efforts. This approach, which has cost billions of dollars and led to hundreds of thousands of deaths around the world, is increasingly criticized as ineffective -- especially by leaders in Central and South America, who have become more receptive to alternatives like drug legalization or decriminalization. While the conversation is beginning to shift, Biden is still touting success in Colombia by pointing U.S. efforts that have led to reductions in cocaine production there. But that production has not disappeared, just migrated south to Peru and Bolivia.

Reports of Biden's interest in a 2016 presidential campaign come at a time of rising public acknowledgment of the damage that decades of reckless drug policy have wrought.

While the U.S. is home to about 5 percent of the world's population, it has a quarter of the world's prisoners. Incarceration levels have surged since the 1970s thanks in part to harsh sentences for nonviolent drug possession and distribution. The penalty increases enacted in Biden-backed legislation during the 1980s and 1990s have been expensive, have put more drug offenders behind bars for longer periods, and yet have not been effective at reducing drug use or recidivism.

Biden isn't the only high-profile Democratic presidential hopeful with a history of backing failed drug war policies.

"Joe Biden would be the third Democrat, alongside Hillary Clinton and Martin O'Malley, with a long record of support for the war on drugs," said Dan Riffle, director of federal policies for the Marijuana Policy Project. "There are candidates in this race with new ideas and rational, health-focused strategies for addressing marijuana use ... but Biden isn't one of them."

Before a campaigning Clinton called for an end to mass incarceration, she actively supported longer and tougher prison sentences and, as first lady, lobbied for Biden's 1994 crime law. She recently explained to Black Lives Matter activists that the law was an honest attempt to address a real problem, though its consequences went beyond what anyone had anticipated. Bill Clinton himself has conceded that the policies of his administration caused a wave of over-incarceration in the U.S. He even apologized to Mexico for the U.S.-led drug war that escalated under the North American Free Trade Agreement he championed.

Meanwhile, unrest between Baltimore police and residents earlier this year following the in-custody death of Freddie Gray has focused attention on that city's use of militarized police tactics and anti-drug efforts that targeted poor and minority communities. O'Malley, the former mayor of Baltimore, has had to explain his decision to embrace and expand such policies during his tenure.

Moreover, Biden, Clinton and O'Malley are not alone in their past support for harsher law enforcement. At the time, political leaders across the spectrum were responding to soaring violent crime rates, which many believed required an immediate, punitive response. The vice president's supporters have also pointed out that he didn't agree with every component of the bills he signed on to.

For example, Biden has been outspoken about his opposition to mandatory minimum sentencing. In 1986, he introduced his own drug bill that contained no mandatory minimums for nonviolent drug offenders. But he ultimately signed off that year on the Anti-Drug Abuse Act, which added more mandatory minimums.

Ahead of the passage of the 1994 crime law, Biden came out against the three-strikes provision, calling it "simplistic." He would also speak out against including mandatory minimums in the legislation.

"I think we've had all the mandatory minimums that we need," Biden said during a 1993 U.S. Sentencing Commission symposium. "We don't need the ones that we have. But quite frankly, I don't think I will prevail. … I've watched how the process works. I am not at all hopeful there will be [enough] senators prepared to vote with me."

More recently, Biden has backed measures to ease some of the tough-on-crime policies he helped create. He aided in the passage of the 2008 Second Chance Act, which aimed to reduce recidivism through the expansion of programs for adult and juvenile offenders as they leave prison.

That same year, the senator vocally supported eliminating the crack/powder cocaine sentencing disparity that he helped push through more than two decades earlier.

"Many have argued that this 100-to-1 disparity is arbitrary, unnecessary and unjust, and I agree," Biden said during a Senate hearing. "And I might say at the outset in full disclosure, I am the guy that drafted this legislation years ago with a guy named Daniel Patrick Moynihan, who was the senator from New York at the time. And crack was new. It was a new 'epidemic' that we were facing. And we had at that time extensive medical testimony talking about the particularly addictive nature of crack versus powder cocaine. And the school of thought was that we had to do everything we could to dissuade the use of crack cocaine. And so I am part of the problem that I have been trying to solve since then, because I think the disparity is way out of line."

Two years later, the Fair Sentencing Act would reduce that disparity to 18-to-1 and eliminate mandatory minimum sentences for simple possession of crack.

In 2013, when the Obama administration allowed recreational marijuana legalization policies to blossom in Colorado and Washington, Biden told Time magazine that he "supports the president's policy" and that convicting people for smoking marijuana was a waste of time and resources.

"I am not only the guy who did the crime bill and the drug czar, but I'm also the guy who spent years when I was chairman of the Judiciary Committee and chairman of [the Foreign Relations Committee] trying to change drug policy relative to cocaine, for example, crack and powder," Biden told Time in 2014.

Sarah Ford, press secretary for the Draft Biden super PAC, declined to comment on his drug and crime policy record, as did the vice president's office.

Overall, Biden's drug policy record is a nearly 30-year work in progress with more lows than highs. While his most significant contributions in this area have done immense damage, his supporters note they were well-intentioned efforts to reach a solution within the U.S. Senate, which has never been a breeding ground for progressive criminal justice policy. His more recent change in tone and willingness to re-examine his positions, they argue, is proof that he's evolving in the right direction.

But voters who see drug policy and criminal justice reform as key issues might be looking for a greater transformation.

"Our hope is that, just as with marriage equality, he demonstrates an evolution on criminal justice," said Michael Collins, policy manager for the Drug Policy Alliance. "Joe Biden should apologize -- just as Bill Clinton did -- for his role in mass incarceration, and he should champion systemic change."

Mark Kleiman, professor of public policy at New York University's Marron Institute of Urban Management, said that Biden's earlier positions are not necessarily good predictors of what his policies would be as president. Kleiman offered another observation about weighing Biden as a candidate.

"The only reliable rule," he said, "is that any Democrat is going to be light-years ahead of any Republican."

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