Like hits, for example. Wanna put a hit out on your wife? Pay a tax to the government and do as you please.
Less crime, since it's no longer illegal.
The War on Drugs failed because of a myriad of reasons. It still fails.
It failed the people it attempted to protect - the families. Families have been destroyed by the millions because someone was imprisoned for years for smoking a plant.
It failed financially.
It was often based on racist reasons ('Reefer Madness', anyone? The crack epidemic in the 80's was another example) or had racial implications that were lopsided.
There really has been next to nothing beneficial from 30 years of it. And nowadays, private enterprises increasingly bar people with felonies from even being gainfully employed. A turned-around felon has a computer application tell him he can't even work at a convenience store because he smoked a plant.
However, once you get past some of the 'low-level' drugs, there is more gray area.
Someone above mentioned "natural" drugs. Opiates are natural. I don't want any opiates or opiate derivatives to be legal. My grandmother was driven off a cliff by doctors when she was pumped full of morphine.
Unfortunately, the topic is too political to discuss in depth on here.
Maybe it's just me, but these two posts seem to be coming from completely opposite ends of this argument's spectrum.
