Despite widespread citizen support for medical marijuana, which is now legal in some form in more than half of the U.S., cannabis remains illegal on the federal level. Some advocates believe that the end of prohibition is inevitable. But according to the Harvard Political Review, there still remains substantial barriers to nationwide legalization. Here’s what they are.

1. Legalization requires research—and research requires legalization

Firstly, one of the main reasons cannabis remains a Schedule I drug under the federal government’s Controlled Substances Act is that the FDA continuously refuses to approve marijuana as a form of medication. Ironically, the FDA has approved synthetic alternatives like Marinol and Syndros, which attempt to recreate the therapeutic benefits of cannabis, but which also present a number of potentially devastating side effects not present in marijuana.

As Harvard outlines, the FDA’s approval process for research is complicated and restrictive. The FDA traditionally reviews the findings of outside research firms. But because these outside research firms must work around the federal governments’ classification of marijuana as a Schedule I drug, this research remains difficult to conduct and therefore scarce.

The Drug Enforcement Agency (DEA) also presents a major research barrier, according to the Harvard Political Review. The agency has consistently blocked efforts for cannabis research, such as the University of Massachusetts’ requests to open a cannabis research facility. This issue is a result of the agency’s classification of cannabis as a Schedule I drug under the Controlled Substances Act. As such, cannabis is considered by the agency to have “no currently accepted medical use and a high potential for abuse.” Other Schedule I drugs include substances like cocaine, opioids and methamphetamines.

Meanwhile, the federal government holds a patent on marijuana entitled “Cannabinoids as Anti-Oxidants and Neuroprotectants,” which contradicts any claims that cannabis has “no currently accepted medical use.”



PORTLAND, ME – AUGUST 25: Sam Koenigsberg smokes prescribed medical marijuana at his home. Koenigsberg was diagnosed with anaplastic astrocytoma, an extremely rare malignant brain tumor, in January and given two to eight years to live. For his 33rd birthday, he threw an amethyst-themed party to bring his friends and family into the world of his ‘purple visions.’ Medical marijuana has played a big role for him in his treatment and Koenigsberg says that it has helped him immensely. He considers himself an advocate of its medicinal purposes. (Photo by Brianna Soukup/Portland Press Herald via Getty Images)

2. Big Pharma is threatened by cannabis

Another major barrier to cannabis research identified by the Harvard Political Review is the influence of Big Pharma on lawmakers in the United States’ federal government. The pharmaceutical industry out-lobbies every other industry in the country, having doled out roughly $2.6 million dollars in lobbying expenditures between 1998 and 2012. Big Pharma’s war against the legalization of cannabis comes with a financial incentive, says Harvard, as legal cannabis could poach billions of dollars of revenue from major pharmaceutical companies.

Since a number of studies show promise for cannabis as a treatment for conditions and illnesses formerly treated with pharmaceuticals—like chronic pain, anxiety and sleep disorders—it’s likely that many patients would swap out pharmaceuticals for medical marijuana. This trend has already begun to take place in legal medical marijuana states.

3. Law enforcement pressures politicians

Harvard also claims that the United States’ law enforcement practices are a major barrier to cannabis research and legalization. This partially has to do with the political power that an endorsement from a sheriff or District Attorney can have for someone running for a local political office. Bypassing this constituency by opposing law enforcement agencies’ positions on marijuana can be, in other words, political suicide.

4. Private prisons oppose legalization

Finally, the Harvard Political Review claims that the private prison industry is one of the principal barriers standing in the way of marijuana legalization and research. Currently, one in five people incarcerated in the United States were charged with nonviolent drug crimes. Without marijuana prohibition, this number would decrease significantly, hindering profits for private prison companies. These profits can be hundreds of millions of dollars.

What now?

The United States Congress is ultimately responsible for legalizing marijuana. As Harvard notes, Big Pharma has given more money to elected officials than any other industry since 1998, targeting both Democrats and Republicans evenly.

What makes these barriers to entry so frustrating to cannabis proponents is their seemingly blatant disregard for public opinion. According to a Quinnipiac University national poll, 94% of voters believe medical marijuana should be legalized. In other words, if the decision were left up to American voters, medical marijuana would surely already be legal.