Harry J. Anslinger wasn't racist, well at least to the extent of my knowledge. What I do know is that the South-Western states did not like Mexicans because they did cheap labor. At this time you have to realize the Great Depression was in session, since Mexicans worked cheap Americans were not getting hired so they became racist. During all this Mexicans smoked Cannabis and they themselves called it Marijuana. So with a mixture of all this crazy shennanigins, the South-Western states urged Harry to do something about, they used to Cannabis as a scape goat saying it made Mexicans commit crime and things of that nature. So the states decided to prohibit Cannabis, so the Mexicans would be driven out the Great ol' free United States of America. Since Mexicans called Cannabis Marijuana the media used the name as a way to make people realize Mexicans used this stuff. The hatred for Mexicans, Black Jazz musicians, and a naive Harry lead to the Marijuana Tax Act of 1937.