[splat]

Prison guard unions would be one. The War on Drugs is a major contributor to the sad statistic that the US has more prisoners than any other country on the planet (not per capita, more prisoners, period). That means good business for prison guards, and the prison guard union wields a disproportionate amount of power, at least in California.

[nate_meurer]

Yes! Exactly right. The prison guard union in California lobbies hard against any attempt at even mild reforms of drug laws. Here's a taste:

http://reason.com/blog/2011/06/07/prison-guards-union-locks-...