Sheldon Richman is senior fellow at The Future of Freedom Foundation in Fairfax, Va., author of Tethered Citizens: Time to Repeal the Welfare State, and editor of The Freeman magazine.

Much is made of how President Obama’s position on same-sex marriage has “evolved” to an endorsement of legalization. One hopes his position on the atrocity called the “war on drugs” is evolving.

It’s not really a war on drugs. It’s a war on people, most of whom have committed no violence or other aggression against person or property. Those who do commit violence are encouraged to do so by the very “war on drugs” that Obama and other enlightened leaders so enthusiastically support. Black markets often feature violence — precisely because they are illegal. Decriminalize the activity, and the violence goes away.

America had a natural experiment in this principle: Prohibition. When the manufacture and sale of alcohol were made illegal by constitutional amendment in 1920, booze didn’t disappear from society. It simply went underground to be dominated by those with a comparative advantage in thuggery. Ending prohibition brought alcohol into the legitimate market (although unfortunately regulated and licensed). The violence related to the manufacture and sale of alcohol went away....