This is such a terrible talking point because decent black people WANTED the government to do something about the crime wave in the 80's and 90's. If anything, Clinton and the other signers of that bill were being more like Republicans in putting forth a "tough on crime" bill. But you have to understand, all that was in the context of a massive amount of gang and drug-influenced violence that was on the rise. Did that negatively impact some poor black and brown people? Sure, but it helped protect a helluva lot of poor black and brown people who were often innocent bystanders, trying to live a normal life.
MAYBE you could point out that Congress could have decreased the prison time served for drug-users and minor possession of drugs (war on drugs implemented by Republican legislators btw), but even then you would be arguing for a more liberal approach to crime, rather than the alternative.
But people who have this knee jerk reaction to pretend like that bill was enforced because of racism against black people, primarily used to unjustly lock up black people, I immediately they are either incredibly ignorant of very recent history, or as you put it "stupid and a c00n".