From Time Magazine's article on decriminalization of all drugs in Portugal:

At the recommendation of a national commission charged with addressing Portugal's drug problem, jail time was replaced with the offer of therapy. The argument was that the fear of prison drives addicts underground and that incarceration is more expensive than treatment — so why not give drug addicts health services instead? Under Portugal's new regime, people found guilty of possessing small amounts of drugs are sent to a panel consisting of a psychologist, social worker and legal adviser for appropriate treatment (which may be refused without criminal punishment), instead of jail. The question is, does the new policy work? At the time, critics in the poor, socially conservative and largely Catholic nation said decriminalizing drug possession would open the country to "drug tourists" and exacerbate Portugal's drug problem; the country had some of the highest levels of hard-drug use in Europe. But the recently released results of a report commissioned by the Cato Institute, a libertarian think tank, suggest otherwise.

The Cato Institute report, published in April, finds that in the 5 years since personal possession of any drug was decriminalized, illegal drug use among teens in Portugal declined and rates of new HIV infections caused by sharing of dirty needles dropped, while the number of people seeking treatment for drug addiction more than doubled.

"Judging by every metric, decriminalization in Portugal has been a resounding success," says Glenn Greenwald, an attorney, author and fluent Portuguese speaker, who conducted the research. "It has enabled the Portuguese government to manage and control the drug problem far better than virtually every other Western country does."

TIME notes "there is a movement afoot in the U.S., in the legislatures of New York State, California and Massachusetts, to reconsider our overly punitive drug laws. Recently, Senators Jim Webb and Arlen Specter proposed that Congress create a national commission, not unlike Portugal's, to deal with prison reform and overhaul drug-sentencing policy. As Webb noted, the U.S. is home to 5% of the global population but 25% of its prisoners."

That is a pretty amazing and depressing statistic. Let's look at the empirical data and use our common sense to decriminalize drug use, or at the least, to decriminalize the use of marijuana.