In fact, drug laws have never worked, as was shown most dramatically in the Prohibition era. Since that time, there has never been a significant correlation between stringent enforcement of drug laws and decreased usage. Hypocritical politicians like you are supporting laws that don't work, and in fact exacerbate many problems associated with drugs. I'm sorry to burst your bubble, but people do use drugs, and they do so even more under your precious proscription schemes. The point is that drugs are addictive.
Drugs are harmful.
One of the things any moral society must do is protect its citizens from avoidable dangers. And that includes drugs. Legalizing drugs will only lead more people to use them. Legalization would be a catastrophe that would destroy the lives of millions. Legalization is surrender to immorality.