Seeking to scare the public away from legalizing the stuff, the Obama administration notes that in 2009, marijuana was "involved in" 376,000 emergency-room visits nationwide. Be afraid, be very afraid: This represents less than 0.3 of 1 percent of all ER visits, and 3.3 million fewer visits than are caused annually by recreational sports. Figures such as those help explain why voters in Washington and Colorado were not frightened, and passed referenda decriminalizing pot.

Oregon rejected a similar measure, just as California did two years ago. But the tide may be turning. On Tuesday, five Michigan cities (Detroit, Flint, Ypsilanti, Grand Rapids and Kalamazoo) and Burlington, Vt., also passed measures relaxing pot laws. Eighteen states and the District of Columbia have approved marijuana for medical use.

Americans are of two minds—at least—about what people should be allowed to put in their bodies. Paternalists in New York; Cambridge, Massachusetts; Richmond, California; and the offices of groups such as the Center for Science in the Public Interest think government should restrict your soft-drink intake. Tobacco smokers are the new Untouchables. But marijuana has a countercultural vibe and is not sold by huge multinational corporations—at least not legal ones, at least not yet. So even though it is bad for you, many progressives do not see much wrong with it.

Illegal multinationals do sell pot, however—quite a bit of it—and it is surprising that Mexican drug cartels did not create super-PACs to lobby against legalization this fall. According to one Mexican think tank, legalizing pot in all three states on Tuesday would have "cut the cartels' income by … about 23 percent." A RAND analysis reached a similar conclusion about California's pot proposition two years ago.

Mexican drug lords aren't the only ones who would see their finances affected. Three decades ago, one incarcerated person out of 10 was a nonviolent drug offender. The ratio is now up to one in four. Marijuana offenders make up only a slice of that slice, yet Harvard economist Jeffrey Miron still estimates that legalizing the wacky weed would save nearly $9 billion a year. Legalizing all drugs would save $41 billion.

But at least that money is well-spent, right? Er, um. … Since 2005, federal spending on the war on drugs has risen 25 percent in nominal terms. Also since 2005, the rate of illegal drug use has risen 10 percent. Marijuana use "is the highest it has been in eight years," the Obama administration noted last year.

Little wonder, then, that U.S. drug czar Gil Kerlikowske admitted two years ago the drug war he spearheads "has not been successful." Or that last year the Global Commission on Drug Policy—whose commissioners include former Federal Reserve Chairman Paul Volcker and former Secretary of State George Schultz—agreed the war on drugs "has failed." Or that this July, New Jersey Gov. Chris Christie also said "the war on drugs, while well-intentioned, has been a failure."

Despite all this, the nation's drug warriors plow ahead, driven by the fear that doing otherwise would be inviting a world where addicts would clog the gutters and third-graders could buy smack at the corner quick-mart. They ought to look at Portugal.

Portugal decriminalized drugs—even the hardest ones—11 years ago. Offenders are now cited for administrative rather than criminal transgressions. A 2009 Cato Institute paper by Slate's Glen Greenwald examined what has happened in Portugal since. And?

The worst fears of drug-war hawks never materialized. Drug use has remained steady or, "in many categories, has actually decreased." HIV infection rates and drug-related mortality rates have dropped. The bogeyman of drug tourism—in which "planeloads of students" fly to Portugal to toke up or shoot up—never showed up. In short, "none of the parade of horrors" predicted by opponents came to pass, while "many of the benefits" predicted by advocates did.

This likely is because "decriminalization was never seen as a concession to the inevitability of drug abuse. To the contrary, it was, and is, seen as the most effective government policy for reducing addiction and its accompanying harms." Persons caught with drugs in Portugal are brought before "dissuasion commissions" whose "overriding goal" is to "avoid the stigma that arises from criminal proceedings. … At all times, respect for the alleged offender is emphasized." Those found to have a substance problem are sent to treatment rather than prison.

That's a sharp contrast to the approach in most of the United States, where the federal government "steadfastly opposes drug legalization." So says the current administration, headed by a man who brags that he once "inhaled (marijuana) frequently" because "that was the point." At least his inhaling had a point, which is more than you can say for our jail-'em-and-forget-'em drug policy.