2) drug use is not necessarily directly correlated with drug crime
3) therefore, equal drug use does not automatically mean unfair prosecution
3) type of drug, extent of use, method of obtaining drugs, involvement with the criminal subculture, amount of crimes committed, type/severity of crimes committed may differ racially, and almost certainly differ with regard to economic status (often correlated with race).
4) Please point me to a specific, reliable source saying that white people are committing exactly the same crimes as black people and being punished differently.
5) Please don't shove me into a political party because I disagreed with your assumptions.
6) I didn't mean that this is a hate crime, that was me kinda going off on an internal tangent and thinking about (slightly) related things. Ignore that.
EDIT: just to clarify, I did read the later posts and I would like to point out that your stats about drug use don't specify the type of drugs or the circumstances, which would have a very important effect on potential drug-related criminal actions.
Also, I don't disagree that there is the possibility (even likelihood) of bias on the side of the police. And I'm not saying that racism doesn't exist or anything like that. I'd just like to point out that that probably isn't the sole reason for the discrepancy.