This Spring could see another key victory in the fight to end America's War on Drugs. On April 4, the Drug Enforcement Administration sent a 25-page letter to U.S. Senators saying that the DEA plans to decide whether or not to reschedule marijuana in the Controlled Substances Act (CSA) in the first half of 2016. So the legal landscape for marijuana could change significantly as early as June.

The DEA's letter was in response to Democratic party senator Elizabeth Warren and seven other senators who have called on the federal government to research marijuana's potential medical benefits. Right now, marijuana is classified as a Schedule I drug in the CSA, which means the federal government officially defines cannabis as a substance that has no medical value and as dangerous as heroin.

However, almost half the country disagrees: despite the federal scheduling, 23 states having legalized medical marijuana to treat conditions such as arthritis, epilepsy and other conditions.

What rescheduling means

There are five distinct schedules in the CSA, so the significance of rescheduling hinges on where marijuana is slotted. The DEA could keep it listed with heroin in Schedule I, group it with oxycodone in Schedule II or even drop it to Schedule V with Robitussin AC.

It's probably wishful thinking to hope that the DEA will shift from banning cannabis completely to letting pharmacies sell it over the counter. So let's focus on what the most conservative step toward reform - changing marijuana from Schedule I to Schedule II - could do.

"Schedule II changes the situation in a very significant way," John Hudak - deputy director of the Center for Effective Public Management and a senior fellow in Governance Studies for the Brookings Institution - told Civilized. "Schedule II substances may have medicinal value. They can be used in extremely regulated settings and for medical treatment."

That move would not only make it easier but also more acceptable for researchers to study cannabis. Hudak noted that marijuana's Schedule I status, "creates cultural biases in universities and research institutions. Universities are pretty conservative places in terms of risk-taking. Donors may not be interested in funding a university researching marijuana because it is a harmful drug with no medical value according to the federal drug scheduling."

So this incremental step wouldn't be a game-changer, but it would allow researchers to test marijuana and perhaps make some breakthroughs regarding its potential health benefits down the road.

Will it happen?

DEA head Chuck Rosenberg has admitted that 'heroin is clearly more dangerous than marijuana.'

There's no shortage of people who want to see marijuana rescheduled or removed from the CSA scheduling entirely. Presidential candidates Bernie Sanders and Hillary Clinton, and Ilya Shapiro of the Cato Institute and Hudak of the Brookings Institution are just some of the many politicians and advocates who are calling for reform. On top of that, activists recently held a smoke-in outside the White House on April 2 to protest the current scheduling of marijuana.

Yet the DEA has repeatedly rejected petitions to reschedule marijuana since it was listed as a Schedule I drug in 1972. The DEA's current head, Chuck Rosenberg, has admitted that "heroin is clearly more dangerous than marijuana." But last September, he dismissed the idea of removing marijuana from the drug schedule, and two months later, he sparked controversy by calling medical marijuana "a joke."

So radical change seems unlikely, but Rosenberg could still surprise us by making marijuana a Schedule II drug. If not, there is a chance that President Obama could override the DEA by rescheduling marijuana via executive order. The Obama Administration poured cold water on that idea last January, but there is some speculation that the president might change his mind. If not, America's best chance for guaranteed reform would be to elect either Sanders or Clinton for president in 2016.

It doesn't look good, based on the recent comments by the president and the DEA head. We'll just have to wait and see whether a radical change of position is in the works.

h/t The Huffington Post, The Washington Post, FOX News, International Business Times