Our elected leaders have been waging their war on drugs for decades now.
The problem with the war, like everything they do, criminals don't follow their many laws to stop the sale / possion / use of drugs. Just law abiding citizens follow their laws, and thus the problem.
Forcing their law on law abiding citizens, does nothing to alter the behavior of the criminals.
Gun laws have the same effect, except with their "gun free zones" they have provided the crininals with killing fields.