The drug war is clearly a farce because of the focus on dealers. If there was a serious desire to reduce usage we know full well from history what "works." You very severely punish anybody caught with stuff, regardless of "intent to distribute."
Consider, for example, that both Trayvon and Michael Brown were high on marijuana when they made decisions that lead to their deaths and ensuing hugely expensive social disturbances. If you care to step out of your upper middle class bubble, it is not at all crazy to suggest that cannabis does in fact have huge negative externalities.
0 - http://en.wikipedia.org/wiki/Shooting_of_Trayvon_Martin#Coun...