Prohibition failed, the war on drugs has failed, even underage drinking and smoking fails.
The government can't stop people from doing what they want to do. All they're doing is making a black market for criminals to get rich from.
The billions spent on drug enforcement would be much better spent on education and supporting high school sports in my opinion.
http://www.drugsense.org/wodclock.htm
Imagine an extra $40 billion a year spent on education and after school programs in poor communities instead of drug enforcement?