It was originally for discrimination purposes. In the early 20th century they blamed the Mexicans and used marijuana as a fear factor and put it on the Mexican Americans. Similar to the early drug epidemic. “Just say no” heroine was considered for blacks meth for whites and marijuana for Mexicans. This was all motivated by labeling.
Another reason was because the prohibition of alcohol once alcohol was allowed it was pressure that made people find a new drug to attack but they needed someone to blame essentially
