Nothing "works" completely whether or not it is made law. Some things work to a pretty good extent, however. We outlawed murder because that works to a pretty good extent.

Outlawing marijuana, however, has failed totally. Outlawing alcoholic beverages has failed totally. Outlawing theft and rape has worked to a pretty good extent.

Now let's take a look at that.

The reason it works to outlaw murder or theft or rape is because it is 100% obvious to 99.999 % of us that they should be outlawed, because virtually everyone thinks they are totally wrong. The same is not true of using marijuana, drinking an alcoholic beverage, or owning a gun.

Have I made myself clear to your satisfaction, Kent?