Earlier quoted context omitted.
"Cannabis prohibition, on the other hand, has historically been targeted explicitly at minorities" Note: targeted at minorities by minorities. The African American community was hugely supportive of the "War on Drugs", until it became clear that it wasn't helping. But seriously, in the 1960s through 1990s, plenty of powerful African American politicians supported the War on Drugs. http://prisontime.org/files/2013/07/…
Cannabis prohibition, starting right from the 1914 El Paso ordinance, unambiguously and often transparently targeted Mexicans. You are talking about a much later stage, when the power dynamic was one of entrenched power.
I do think it is important to remember that the African American community was pretty happy with the inception of the "War on Drugs" however.