This is nothing but a scam to take us down the road to legalization (aka, Taxation) of ALL now-illegal drugs.
56% Favor Legalizing, Regulating Marijuana (Rasmussen Reports May 17, 2012)
You do realize that there are many municipalities and states that have decriminalized marijuana, some for decades now, and none of them have even hinted at following the logical leap that you are positing, right?