Edit:
Tt is immoral to initiate aggression against peaceful people. It is not a crime to engage in behavior that does not directly harm the person or property of others without their consent, even if there is a statutory prohibition. Indeed, all acts that lead to the harm of individuals or their property are crimes even if statutorily allowed.
No one who believes that initiating violence against others is wrong can support drug prohibition. The advocates of prohibition would say that "drugs harm society", but "society" is not a thing that exists in reality but is merely a label for an aggregate of individuals, and therefore cannot be shown to be harmed unless specific individuals can be shown to be harmed by the drugs or the use of the drugs by other individuals. Obviously, it's not the possession, distribution, or use of the drugs that causes one individual to harm another, but related activities. In principle, then, only those related activities, such as shooting one's competition in the drug trade or beating a prostitute and forcing her to take drugs, are crimes and as such should lead to punishment, and perhaps a harsher punishment than is usually provided now.
Prohibition and punishment of peaceful individuals because some individuals have acted irresponsibly is a collectivist, authoritarian notion and is the advocation of violence as a tool to regulate behavior that has not, in itself, caused harm.
Discuss.