It was pre-fabricated. Nixon and aide, John Ehrlichman, the brainchild of the Watergate scandal, decided to create the war on drugs specifically to go after two groups of people.
"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?" Ehrlichman was quoted as 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."
This is stark raving mad. The entire war on drugs was created to politically persecute enemies of Nixon's corrupt government. Nixon, of course, later resigned facing corruption charges.
So why are his corrupt policies still in place?
Fortunately, we are in the midst of a global awakening. The internet has allowed us to diffuse information regarding the medical value of cannabis, including THC's ability to destroy cancer while leaving healthy cells unhindered.
We are on the verge of a federal shift towards legalizing pot. As more states jump on board with, both, medical and recreational pot, the feds lean more towards leniency and eventual legalization. In this case, the federal government follows the will of the states and not the other way around.
Nixon's "war" put a lot of people in jail that could have otherwise helped the United States diversify and integrate. Now is the time to throw full support behind legalizaion.