Drug war takes a hit with softer sentence

The United States has been waging an ostensible war on drugs for decades now. I have one silly question: Recently the mandatory sentence for crack cocaine was lowered by the U.S. Sentencing Commission to the level of powder cocaine, so couldn’t we just as easily raise the sentence for powder instead?

It seems that would be a greater deterrent than letting already sentenced and incarcerated felons out early. Just a thought.