Possible, but unlikely. According to a recent study, the majority of offenders are sentenced for violent offenses, and the majority of those sentenced for violent offenses have never been convicted of a drug crime.
Please post the study.
We should end the war on drugs, of course, but we more urgently need to end what Ta-Nahisi Coates calls "the carceral state", and that will require much stiffer medicine than drug legalization.