Statistics are what you make them, considering that blacks are more likely to victims of violence to other blacks, when they are not the majority, how can the outcome of incarceration rates be remedied?
[1] http://www.bjs.gov/index.cfm?ty=pbdetail&iid=1118
[2] http://m.chicagoreader.com/chicago/chicago-marijuana-arrest-...
The amount of time and money spent dealing with cannabis is mind-boggling. About 50,000[1] Mexicans have been murdered in the recent drug wars. Some of those are because cannabis is illegal.
Cannabis prohibition is going to be viewed with horror in the future.
(http://www.time.com/time/world/article/0,8599,2084224,00.htm...)
(http://www.nytimes.com/2012/11/02/opinion/hit-mexicos-cartel...)
(http://www.drugpolicy.org/drug-war-statistics)
(http://fdlaction.firedoglake.com/2010/05/05/fbi-marijuana-is...)
[1] numbers are hard to check, but some people say 62,000 since 2006.