Costs and Benefits

I couldn’t help but wryly note that the New York Times published a time-pegged article on the state of play in marijuana politics for April 20th.  “420” is a common slang term for marijuana, and April 20th (4/20) is, according to the article, often accordingly known as the “High Holiday”.  I don’t actually think that the relatively stodgy Times is full of drug users, but merely that this reflects a real, growing debate over the proper legal attitude towards marijuana.  Many states now have medical usage, and in 2008 Massachusetts passed a decriminalization law, via a ballot initiative which won the state with a bigger margin than Barack Obama.  I’ve noticed, however, that all too often, arguments over marijuana law involve a lot of giggling and people not really taking pro-legalization arguments seriously, especially if posed by young people.
This is stupid.  You can’t just dismiss arguments about any policy that puts so many people in prison, especially one where the impact is directed so disproportionately at the poor and minorities.  The drug cartels that are challenging the Mexican government derive 60% of their revenue from marijuana, a percentage that would immediately drop to near-zero with legalization.  Marijuana policy is a very real subject, with very real costs and (presumably) very real benefits. But the War on Drugs has brought very little in the way of concrete results, while it has done enormous damage to the Bill of Rights, the state of Mexico, and the lives of millions of American citizens.  If Obama can stand up before the nation and tell us that we’re winning the War on Drugs, he is clearly deluded or lying.  And if he says we’re not, why would we continue such a fruitless struggle?  If this were a war in, say, Southeast Asia, we would have long ago declared victory and went home.
As a theoretical aside, in a liberal state which respects the right of citizens to their own bodies, shouldn’t the onus be on prohibitionists to prove that prohibition is not only better, but necessary? I think we should have a fairly high bar of need for a policy which intrudes so forcefully into private life, such as a real threat to the ability of civil society to function, which I’m not really sure is a threat any currently existing drug poses.  And if we do determine that to be the case, how can we justify our actions against drugs either more benign (marijuana) or far less widespread (cocaine, LSD) than the most widespread and damaging drug in our society, alcohol?  Totally aside from the pragmatic implications of prohibitionist policy, the philosophical case for selective prohibition just doesn’t hold together that well.  Consistency demands either decriminalization of everything, or aggressive intervention against alcohol, nicotine, and caffeine, all of which constitute very considerable public-health harms.  And I don’t want you to take away my coffee.