Libertarians don't deny that legalized drug use has societal consequences - just as they don't deny that Free Speech and Freedom of Religion have societal consequences. But, importantly, they believe that the sovereignty of the individual over his own body trumps govt. jurisdiction.
Regards,
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That is all well & good, but to achieve that you would have to convert all the junkies in the USA to Libertarians that wouldn't burglarize homes or shoplift, etc. to support their habit...then overdose/die with individual sovereignty by themselves w/o calling a ambulance or going to the ER. Which leads me to the 2nd requirement of "individual sovereignty"...the government would have to exit the medical/medical insurance business (no Medicaid or Medicare or ACA/"Obamacare"). i.e. "the government pays the bills, the govt. makes the rules"....helmet laws, seatbelt laws, etc., etc..