Man has repeatedly proven that he is incapable of being perfect. That's why we have rules, regulations and laws.
So then, you are okay with government telling you what substances you can or cannot put into your own body? You are okay with Bloomberg’s soda and salt restrictions in NYC, for instance?
I’m not talking about a drug dealer shooting someone or an addict stealing from someone to get drug money. Those are crimes and should be prosecuted as such. I just see no difference between someone smoking marijuana in his own home and harming nobody but himself and someone smoking a cigarette in his own home and harming nobody but himself. If I’m wrong, then what is the major difference between the two cases other than the fact that one is legal and one is not (at least in most states).
BTW, which rules, laws, or regulations have allowed man to achieve perfection? Even with such, man remains imperfect. The goal of rules, laws and regulations should be to protect one citizen from having harm done to him or her by another citizen. It should not be to protect someone from doing harm to himself.