They call it War on Drugs, because "War on Blacks" would be racist and "War on the Poor" would be admitting to class warfare.
Think about the simplest example: crack vs. powder cocaine. Prior to 2010, there was a 100:1 ratio on the Federal penalties for the two types of the same drug. Crack cocaine also carried a five year mandatory minimum. Officially, this was based on Congress's belief that crack was more dangerous than powder. Unofficially, it was because crack was much, much more common among blacks and Hispanics, whereas powder was often consumed by rich white people.
In 2010 Obama reduced the disparity to 18:1 and removed the mandatory sentencing on crack. The disparity is still crazy racist however.