I know I'm late on this, but for the last time, Michael Gerson's arguments in support of the war on drugs are pretty silly:
Even by this permissive standard, drug legalization fails. The de facto decriminalization of drugs in some neighborhoods — say, in Washington, D.C. — has encouraged widespread addiction. Children, freed from the care of their addicted parents, have the liberty to play in parks decorated by used needles. Addicts are liberated into lives of prostitution and homelessness. Welcome to Paulsville, where people are free to take soul-destroying substances and debase their bodies to support their “personal habits.”
As Edward Crane points out, D.C. is an example of where the war on drugs has been waged with zeal rather than an example of "de-facto decriminalization."
For reasons I've outlined before, I'm not a proponent of full legalization, but if you really wanted an example of "de-facto decriminalization," you could look to the northeastern elite private colleges where in the absence of real prohibition, the children of the wealthy and connected trade in narcotics facing next to zero consequences if actually caught. Rather than their less wealthy counterparts, who face prison terms that can be a serious impediment to seeking the low-wage licit work that's available, they face institutional punishments like suspended eviction that don't really affect their future career prospects -- and if they do end up in the hands of law enforcement, as "good kids," they still face minor punishments. As a result, it's a relatively simple matter for college kids who get involved with drugs to go on to lives as upstanding members of society, including running for president of the United States. On the other hand, where prohibition is enforced most harshly, the drug trade ends up being competitive and violent, helping to produce the kind of social problems Gerson seems to want to alleviate.
