Washington DC - As Democrats rally around marijuana legalization, President Joe Biden remains hesitant to fully embrace the idea, which some advocates say may be wasting an opportunity to appeal to a wide variety of voters.

"It’s an enormously powerful public policy lever," said Pennsylvania Lt. Gov. John Fetterman, a Democrat who is running for US Senate in the key swing state on a platform of marijuana legalization.

Fetterman called marijuana legalization the "big bazooka" that both Biden and then-President Donald Trump failed to use in the hotly contested 2020 election. Democrats shouldn’t repeat that mistake in future elections, he said.

"Whoever owns legal weed nationally, it’s all gravy. There’s no downside. None. When South Dakota democratically votes for it, in what circles is this controversial?" Fetterman said, noting that voters in deep red South Dakota approved recreational marijuana in the same year the state went strongly for Trump.

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"When South Dakota and California agree on something, that should be a new national law," said Fetterman, whose own state has not yet approved recreational use.

An April poll from Pew Research found that 60% of adults said marijuana should be legal for both medical and recreational use, 31% said it should be legal for medical use, while 8% supported full prohibition.

Advocates point to those polls as a reason Biden would benefit politically if he fully supported legalization.

Biden was one of the main architects of the 1994 crime law that critics say escalated prosecutions of minor drug offenses and led to mass incarceration, but he has since softened his stance.

Biden supports federal decriminalization of marijuana, which would do away with federal prison time for minor offenses, but stops short of making the drug legal.

He has yet to join the growing chorus of Democrats calling for full legalization of recreational marijuana, which include Senate Majority Leader Chuck Schumer of New York among other party leaders.

The distinction is between whether marijuana will still be treated as an illicit substance or a legal product similar to alcohol or tobacco. In July, Schumer proposed removing marijuana from the Controlled Substances Act and setting up a new excise tax on cannabis products.

"Nothing has changed," White House press secretary Jen Psaki said at the time when asked if Biden agreed with Schumer’s proposal.

Under current federal law, marijuana is classified as a Schedule I substance, which is the most severe category that includes heroin and other drugs "with no currently accepted medical use and a high potential for abuse," according to the Drug Enforcement Agency.

Despite the federal government’s designation, 36 states have enacted laws allowing marijuana use for medical purposes. The federal designation is commonly pointed to by policymakers in other states as the reason to keep marijuana illegal.

First-time federal offenders can face a year in prison for possession and vendors in states with legal marijuana face major hurdles to access to banking because of the federal prohibition.

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Both Schumer’s proposal and House Democrats’ proposed Marijuana Opportunity Reinvestment and Expungement Act, would remove that designation entirely in an effort to give the green light to states to enact full legalization – which 18 states have already done despite the federal prohibition.

Biden, on the other hand, has said he wants to redesignate marijuana as a Schedule II substance under the Controlled Substances Act. That is the same designation as cocaine and methamphetamine and would still classify marijuana as a drug with a high potential for abuse, according to the DEA.

Biden has said the redesignation would enable medical research to study the long-term effects of marijuana use, but legalization advocates say that approach is out of sync with current political and scientific realities.

"His policy on marijuana is a very antiquated one, very out of date," said Martiza Perez, director of national affairs at the Drug Policy Alliance. "I think that’s just his personal belief. If he were persuaded by science, the science tells us that marijuana does have positive therapeutic and medical effects, but he still seems very reluctant to just embrace it."

Asked why Biden prefers redesignation of marijuana to a lower classification rather than fully legalizing it, the White House pointed to Psaki’s comments from an April briefing.

"The president supports leaving decisions regarding legalization for recreational use up to the states; rescheduling cannabis as a Schedule II drug so researchers can study its positive and negative impacts; and, at the federal level, he supports decriminalizing marijuana use and automatically expunging any prior criminal records," Psaki said at that time.

"He also supports legalizing medicinal marijuana," she added.

Biden’s deference to states on decisions about recreational use will maintain the current patchwork of state laws, which can lead to people facing stiff penalties for possession depending on which side of a state border they’re standing on, legalization advocates say.

For example, recreational marijuana is a multibillion-dollar legal industry in Colorado, but in bordering Kansas, possession of marijuana can land a first-time offender six months in jail and a lifetime ban from food assistance programs on a second offense.

Justin Strekal, the political director of the National Organization for the Reform of Marijuana Laws, said Biden’s reluctance to back legalization does a disservice to the administration’s broader push for racial justice.

He pointed to a 2020 American Civil Liberties Union report that found between 2010 and 2018 Black people were nearly four times as likely to be arrested for marijuana possession than white people despite similar rates of usage.

During the presidential primary campaign, Biden said he supported expungement of criminal records for nonviolent marijuana offenders after a heated exchange with Democratic Senator Cory Booker from New Jersey, who was hammering Biden on the racial disparity in drug enforcement.

Strekal called for Biden to use an executive order to expunge federal marijuana convictions. "This could be done with the stroke of a pen," he said.

Booker, who is partnering with Schumer on the Senate proposal to decriminalize marijuana and expunge convictions, did not refer to Biden by name this week when asked about the issue.

"For decades, our federal government has waged a War on Drugs that has unfairly targeted communities of color. While red and blue states across the country continue to legalize marijuana, the federal government continues to lag woefully behind," Booker said in a statement.

"It’s time we legalize marijuana, expunge federal non-violent marijuana crimes, reinvest in communities most impacted by unfair drug laws, and finally end the failed federal War on Drugs," Booker said.

Some Republicans agree that action should be taken by Biden or Congress to reduce the adverse effects of marijuana convictions.

"I’ve always been in favor of trying to give people second chances and I think that criminal penalties on most non-violent drug crimes have been too extensive," said Sen. Rand Paul of Kentucky.

"Most of the time, things should be done through legislation, but I’ve also been in favor of pardons that have been given," he said.