Do I care what they are in jail for? Nope. The link between drugs and drinking and violence is close enough that I don't need to worry the details. So that bit of your argument is just another strawman.
Can we use that info? Even Jesse Jackson, in a brief moment of honestly, noted that he uses it when deciding who to worry about when walking down the street.
Liberals talk about the ideal of a color-blind society, but they don't believe it for a second. If they did, your typical white liberal would just as soon live in a black inner city neighborhood as in their lily-white suburbs and gated communities. But they don't.
Sometimes it seems as though the only people who do believe that race has nothing to do with crime are a handful of Republicans who bend over backwards at every opportunity to prove to liberals and to the media how enlightened and non-racist they really are.