The drug war is wholly illegal and unconstitutional. If one recalls, in 1919 the federal government had to enact the 18th amendment to ban the use of alcohol for citizens in the U.S. President FDR then had to push for the passage of the 21st amendment in 1933, to reverse the damage done from their prohibitionist policies. No such amendment to the Constitution was created for these new "banned" substances, and as a result, the drug war is one of the biggest examples of the breakdown in the Rule of Law in our republic. The federal government has never had the legal power to prevent Americans from obtaining and using mind altering substances, however they have assumed this power through misinformation and the general ignorance exhibited by Americans regarding their Constitutional rights.
Every time the DEA raids a medical cannabis facility, or a police officer arrests someone for possession, they are violating their sworn oath to uphold and protect the Constitution.
This history of the illegal drug war is a long one. It has been ongoing in some fashion since President Nixon declared the "War on Drugs" in June of 1971. He then moved to create the Drug Enforcement Administration just 2 years later. At the time, Nixon and the Vietnam War was very unpopular, and the one common thing that a large portion of his opponents shared, was that they used cannabis. Nixon's reasons for enacting the drug war were not clear until recently, when one of his key officials (John Ehrlichman) recounted discussions he had with the president regarding the anti-war left, and African Americans. Ehrlichman said in an interview with Dan Baum "The Nixon campaign in 1968, and the Nixon White House after that, had two enemies: the antiwar left and black people. You understand what I’m saying? We knew we couldn't make it illegal to be either against the war or black, but by getting the public to associate the hippies with marijuana and blacks with heroin, and then criminalizing both heavily, we could disrupt those communities. We could arrest their leaders, raid their homes, break up their meetings, and vilify them night after night on the evening news. Did we know we were lying about the drugs? Of course we did."
While some have tried to cast shade on Ehrlichman's comments, the fact is that scientific research of the time did not support Nixon's attack on cannabis and the other drugs swept up in the drug war. In fact, there were multiple governmental studies conducted during this time, and all of them proved the effectiveness of cannabis at treating several chronic disorders, and almost none showing any negative side effects.
It wasn't just Nixon who had skin in the game, however. William Randolph Hurst was one of the most influential