Here's an encouraging report on progress made since 2010 when the law was changed to eliminate the sentencing disparity between powder and crack cocaine: http://www.ussc.gov/Research_and_Statistics/Federal_Sentencing_Statistics/FSA_Amendment/2013-07_USSC_Prelim_Crack_Retro_Data_Report_FSA.pdf

We need to see more of that sort of thing.

Here's a left-winger's view of the report http://thinkprogress.org/justice/2013/08/02/2405751/slashing-racist-crack-sentences-has-already-saved-16k-prison-years-and-half-a-billion-dollars/