I'm also strongly against drug use, and think society should discourage it through education.

On the other hand, the war on drugs is destroying Mexico, and is not stopping drug use here in the States. I just don't think we can afford the drug war's costs (social, foreign policy, and monetary) any more. If you can't teach your kids to stay off drugs, I'm sorry, but they're on their own, as far as I'm concerned.

Edit: I don't live in California, and haven't looked at Prop 19 in detail.