One of Biden's biggest vulnerabilities is his long record pushing strict drug policies and "tough-on-crime" laws.
Tony Papa, media strategist for the Drug Policy Alliance and former prisoner, is not excited about Biden's bid.
"As a former drug war prisoner I would say Biden's record on drug reform is horrible," Papa tells Raw Story.
"He has an extraordinary long record of supporting the war on drugs and he should be ashamed of it. Nothing can change all the lives he has destroyed by doing this."
And many of the young candidates have already staked out an aggressive legalization stance.
Here are where all the candidates stand on drug policy -- and their history on the issue.
1. Joe Biden
Unlike many other presidential contenders, Biden has not come out in favor of marijuana legalization.
Biden was instrumental in crafting some of the harshest crime legislation in the past two decades, including sponsoring the 1994 crime bill, which cemented mandatory minimums for drug crimes and helped fuel mass incarceration around the country.
He's promoted asset forfeiture, boasting that, "The government can take everything you own, from your car to your house to your bank account!"
Biden also called for the death penalty for drug dealers, a policy proposal echoed by President Donald Trump today.
“There is now a death penalty,” he said in a 1991 floor speech. “If you are a major drug dealer, involved in the trafficking of drugs, and murder results in your activities, you go to death.”
2. Cory Booker
Sen. Cory Booker (D-NJ), has come out as a strong advocate for legalization tied to policies of social and racial justice, like the expungement of marijuana arrest records.
Asked if her would back full pardons for federal marijuana crimes in a CNN town hall, Booker voiced his support.
“Absolutely,” he said. “The war on drugs has been a war on people,” Booker said. “As president of the United States, your job is to pursue justice. And what we see right now is so many folks suffering.”
“If I am your president I am going to fight to make sure that we have sane drug laws and that we expunge the records of those people who are going through convictions and the aftermath for things like marijuana,” he said.
Although Booker has been praised for embracing legalization, some critics argue that his proposed legislation -- the Marijuana Justice Act -- doesn't go as far as other legislation.
"While Booker's bill requires expungement of records related to 'marijuana use or possession offense[s],' Rep. Lisa Blunt Rochester's (D–Del.), applies to 'any Federal nonviolent offense involving marijuana.'" Jacob Sullum wrote in Reason. "That's an important difference, because almost all simple possession cases are prosecuted at the state level, while federal cases typically involve manufacture or distribution."
2. Pete Buttigieg
The Mayor of South Bend, Indiana, Pete Buttigieg said vaguely referred to the end of prohibition -- without setting forth any major policy ideas.
“The safe, regulated, and legal sale of marijuana is an idea whose time has come for the United States, as evidenced by voters demanding legalization in states across the country,” he told The Boston Globe.
Buttigeig recalls getting caught with a joint at Harvard. He observed that the officer berated him as "arrogant" before driving off, without arresting him, prompting Buttigeig to reflect on his white privilege.
3. Julian Castro
The former Mayor of San Antonio told the Boston Globe that he believes in legalization.
“We can sensibly legalize marijuana use with reasonable controls in place,” Castro said.
In 2017 he criticized the White House for apparently weighing cracking down on pot at the state level.
"The White House may crack down on recreational marijuana use— even in states where voters have approved it," Castro wrote on Facebook. "That's a mistake."
4. John Delaney
Delaney, former US Representative from Maryland, has consistently voted to loosen marijuana restrictions in his state, although he's never introduced his own legislation, according to Marijuana Moment.
He also criticized Jeff Sessions' Department of Justice for revoking the Cole Memo, which directed federal agencies to stop cracking down on pot operations in places it's legal at the state level.
"The Cole Memo provided clear guidance to an otherwise conflicting situation,” he told the Washington Post. “Revoking the Cole Memo will restore that confusion and undermines the will of the voters in several states.”
5. Tulsi Gabbard
When Rep. Gabbard (D-Hawaii) launched her Presidential election bid, she railed against a criminal justice system that “puts people in prison for smoking marijuana while allowing corporations like Purdue Pharma, who are responsible for the opioid-related deaths of thousands of people, to walk away scot-free with their coffers full.”
She supported a wide range of anti-prohibition measures, including acting as lead Democratic cosponsor of a measure to federally de-schedule marijuana.
6. Kirsten Gillibrand
Sen. Kirsten Gillibrand (D-NY) co-sponosred the Marijuana Justice Act, alongside Sen. Cory Booker (D-NJ).
“Millions of Americans’ lives have been devastated because of our broken marijuana policies, especially in communities of color and low-income communities,” said Senator Gillibrand. “Just one minor possession conviction could take away a lifetime of opportunities for jobs, education, and housing, tear families apart, and make people more vulnerable to serving time in jail or prison down the road."
"The reality that my 14-year-old son would likely be treated very differently from one of his Black or Latino peers if he was caught with marijuana is shameful," she added.
"Legalizing marijuana is a social justice issue and a moral issue that Congress needs to address, and I’m proud to work with Senator Booker on this legislation to help fix decades of injustice caused by our nation’s failed drug policies.”
7. Kamala Harris
The Senator from California has said she's smoked pot in college -- but prompted a brief backlash when she said she listened to the music of Tupac, which did not exist at the time.
On policy, Harris is a strong proponent of legalization that includes a racial and social justice component such as record expungement.
8. John Hickenlooper
As the former Governor of Colorado Hickenlooper oversaw legalization efforts in the state, although he initially called the policy "reckless." Colorado has also faced critique for creating a legal pot market that didn't do enough to make up for the impact of prohibition communities and people of color.
Hickenlooper denounced federal plans to crack down on Colorado's legal pot markets under the Sessions DoJ.
"And by the way, I don’t think any of us are wild about Washington telling us what’s good for us,” he said in 2017. “We expect that the federal government will respect the will of Colorado voters.”
9. Gov. Jay Inslee
Governor Jay Inslee of Washington oversaw the legalization of marijuana in his state. He's also been a harsh critic of federal efforts to crack down on businesses that are legal at the state level. He's got an A+ rating from NORML, a group devoted to ending prohibition.
10. Amy Klobuchar
Sen. Amy Klobuchar (D-MN) told the Washington Post that she supports legalization.
"I support the legalization of marijuana and believe that states should have the right to determine the best approach to marijuana within their borders," she said in February.
11. Wayne Messam
Wayne Messam -- Mayor of Miramar, Florida -- believes in states rights when it comes to marijuana.
"As long as those states that choose to do so continue to enforce DUI laws, spread economic benefits throughout all communities, and expunge records for those arrested for selling marijuana, they would have my full support as President,” according to his campaign website.
12. Seth Moulton
Rep. Seth Moulton of Massachusetts has embraced marijuana legalization and regulation in the interest of safety. "People are going to use marijuana whether we like it or not," he told Axios. "So let’s make it legal and let’s regulate it to make it safe."
13. Beto O’Rourke
Former Texas Rep. Beto O'Rourke (D-Texas) has been a passionate proponent of marijuana legalization for almost a decade. The issue helped usher him into office in a 2012 Texas House primary. He also made it a focal point of his challenge to Sen. Ted Cruz (R-TX). He supports legalization at the federal level. He's also denounced the racial bias of the US criminal justice system.
"Many have called this part of the New Jim Crow, and for good reason," he's written.
14. Tim Ryan
Rep. Tim Ryan (D-Ohio) is a strong proponent of legalization, despite having doubted it in the past due to his work with addiction.
In an op-ed published on CNN during the summer, he made the case for legal pot in the entire U.S.
"Marijuana should be legal in all 50 states," he wrote.
"Across the country, nine states and the District of Columbia have passed laws legalizing marijuana."
"Voters in Michigan and Oklahoma will be voting on marijuana initiatives this November, and efforts are underway in Missouri, Arizona, Nebraska and Utah to get legalization initiatives on the ballot. While I support these states for leading by example, this is an issue that affects every corner of our nation. You should not be able to legally buy a product in one state, just to be arrested for the very same act in another."
15. Bernie Sanders
Vermont Sen. Bernie Sanders has long blasted American's war on drugs.
“How many young people’s lives got off to a bad start because of a police record related to marijuana?” he writes, noting that even a simple possession conviction can make it more difficult to find a job, rent an apartment or get admitted to college," he wrote in his latest book.
“The good news is that many states and cities across the country are taking action to undo the damage caused by the war on drugs,” Sanders adds. “More and more states are moving to decriminalize or legalize the possession of marijuana, and some have passed legislation to expunge prior misdemeanor convictions.”
16. Eric Swalwell
Rep. Eric Swalwell (D-CA), a former prosecutor, believes that police resources could be better used than in busting people for pot. He's tentatively come out in favor of legalization.
“I believe that citizens in states across the county should be empowered to make their own decisions as to how to treat marijuana,” said Swalwell. “The people of California voted to allow patients access to medical marijuana, and the federal government should not stand in their way," he said.
"Likewise as a prosecutor, I saw firsthand the needs of local law enforcement, and we should be directing the hundreds of millions of dollars currently spent on marijuana enforcement to more serious priorities. These bills are good for the economy, patients and states’ rights.”
17. Elizabeth Warren
Elizabeth Warren (D-MA) supports legalization, although she had her doubts in the past. Her current position is that states should decide.
"The federal government needs to get out of the business of outlawing marijuana. States should make their own decisions about enforcing marijuana laws," she tweeted.
She's also backed a spate of bills that would loosen prohibition, from marijuana de-scheduling to research on pots therapeutic effects on veterans.
18. Marianne Williamson
Oprah's spiritual guru Marianne Williamson has voiced her support for legalization.
"We should legalize marijuana & release nonviolent offenders who’ve been incarcerated because of it," she posted to Twitter.
"The most dangerous drug dealers in America are legal pharmaceutical companies that knowingly overmanufacturer, falsely advertise & promote overprescription of addictive substances."
19. Andrew Yang
Businessman and tech start-up founder Andrew Yang has pledged to legalize and also said he'd pardon all non-violent drug offenders on 4/20.
