The first thing those who wish to legalize drugs trot out is prohibition. I have generally taken to either ignoring or mocking the comparison, but as I don't recall whether or not you have seen my previous comments on prohibition, I will give a quick synopsis of what I think about it.
I think the 18th amendment was a mistake. It was a foolhardy mistake. I concede that Alcohol is a drug, and that it causes yearly devastation in lost/destroyed lives and property damage. I think the world would probably be better off without it, but I also think that genie was let out of the bottle a long time ago.
Alcohol has been established in human society since known history began. It was simply irrational to believe that you could eliminate something which is so ingrained into a society simply by passing a law.
Other drugs are relatively new, and have not permeated through society in the manner that alcohol has. Alcohol is a special case where it is simply not reasonable or practical to eradicate it, and society has counted the losses it suffers on account of it as acceptable.
That alcohol is an exception does in no way justify the emergence of new "alcohols" to add to it's death toll, especially when the evidence indicates that these addictions are open ended, and appear capable of expanding to an ever increasing number of the population, and in ever increasing severity as to consequences. This thread topic appears to be a prime example of the phenomena in action. We are even now seeing increase in usage, and if we open the legal door for marijuana, we will have no arguments with which we can close it on cocaine and opium.
We have seen what opium has done to China, and it is readily apparent to me that Opium is an existential threat to any nation that cannot stop it from coming into it's borders.
The answer is to close the door when it's little, because when it's large, it will be impossible to close it. (same on immigration.)
You should probably take a look at “The War on Drugs” and the results from it.
It qualifies for the definition of insanity: “Doing the same thing over and over, expecting different results.”
America will be better off with marijuana decriminalized/legalized, and other very dangerous substances kept illegal (meth, heroin).
And “lack of capacity due to intoxication” should not be a defense or mitigating factor in criminal/civil cases for alcohol or drugs.
In California they are charging 2nd degree murder for deaths due to drivers’ intoxication.