Actually, when William Hearst originally started the campaign in the 20s to take out the hemp farmers that were competing with his timber business (he bought up most of Humboldt so he could corner the paper market), he targeted Hispanics (primarily Mexicans) with Marijuana in his articles about drug crimes and how they were ruining America. Henry Ansligner bought it hook, line and sinker, and he set the tone until the 40s, when hemp was briefly made legal for the war effort. Note that Jack Herer's The Emperor Wears No Clothes does an excellent job illustrating this historical relationship.

Once the Beats started smoking weed in 50s, hemp was criminalized again, and the prohibition was expanded to felony status as law enforcement started targeting the evolution of the Beat movement, the hippies.

The subsequent prohibition on cocaine products was targeted at black neighborhoods (as per the GOP intention during the Nixon/Reagan era), and was built upon the "successes" of the previous marijuana prohibition.

This is why I don't think they'll stop at porn.