NEVER before have so many Americans supported decriminalizing and even legalizing marijuana. Seventy-two percent say that for simple marijuana possession, people should not be incarcerated but fined: the generally accepted definition of "decriminalization." Even more Americans support making marijuana legal for medical purposes. Support for broader legalization ranges between 25 and 42 percent, depending on how one asks the question. Two of every five Americans--according to a 2003 Zogby poll--say "the government should treat marijuana more or less the same way it treats alcohol: It should regulate it, control it, tax it, and only make it illegal for children."

Close to 100 million Americans--including more than half of those between the ages of 18 and 50--have tried marijuana at least once. Military and police recruiters often have no choice but to ignore past marijuana use by job seekers. The public apparently feels the same way about presidential and other political candidates. Al Gore, Bill Bradley, and John Kerry all say they smoked pot in days past. So did Bill Clinton, with his notorious caveat. George W. Bush won't deny he did. And ever more political, business, religious, intellectual, and other leaders plead guilty as well.

The debate over ending Marijuana prohibition simmers just below the surface of mainstream politics, crossing ideological and partisan boundaries. Marijuana is no longer the symbol of Sixties rebellion and Seventies permissiveness, and it's not just liberals and libertarians who say it should be legal, as William F. Buckley Jr. has demonstrated better than anyone. As director of the country's leading drug-policy-reform organization, I've had countless conversations with police and prosecutors, judges and politicians, and hundreds of others who quietly agree that the criminalization of marijuana is costly, foolish, and destructive. What's most needed now is principled conservative leadership. Buckley has led the way, and New Mexico's former governor, Gary Johnson, spoke out courageously while in office. How about others?

A SYSTEMIC OVERREACTION

Marijuana prohibition is unique among American criminal laws. No other law is both enforced so widely and harshly and yet deemed unnecessary by such a substantial portion of the populace.

Police make about 700,000 arrests per year for marijuana offenses. That's almost the same number as are arrested each year for cocaine, heroin, methamphetamine, Ecstasy, and all other illicit drugs combined. Roughly 600,000, or 87 percent, of marijuana arrests are for nothing more than possession of small amounts. Millions of Americans have never been arrested or convicted of any criminal offense except this. Enforcing marijuana laws costs an estimated $10-15 billion in direct costs alone.

Punishments range widely across the country, from modest fines to a few days in jail to many years in prison. Prosecutors often contend that no one goes to prison for simple possession--but tens, perhaps hundreds, of thousands of people on probation and parole are locked up each year because their urine tested positive for marijuana or because they were picked up in possession of a joint. Alabama currently locks up people convicted three times of marijuana possession for 15 years to life. There are probably--no firm estimates exist--100,000 Americans behind bars tonight for one marijuana offense or another. And even for those who don't lose their freedom, simply being arrested can be traumatic and costly. A parent's marijuana use can be the basis for taking away her children and putting them in foster care. Foreign-born residents of the U.S. can be deported for a marijuana offense no matter how long they have lived in this country, no matter if their children are U.S. citizens, and no matter how long they have been legally employed. More than half the states revoke or suspend driver's licenses of people arrested for marijuana possession even though they were not driving at the time of arrest. The federal Higher Education Act prohibits student loans to young people convicted of any drug offense; all other criminal offenders remain eligible.

This is clearly an overreaction on the part of government. No drug is perfectly safe, and every psychoactive drug can be used in ways that are problematic. The federal government has spent billions of dollars on advertisements and anti-drug programs that preach the dangers of marijuana--that it's a gateway drug, and addictive in its own right, and dramatically more potent than it used to be, and responsible for all sorts of physical and social diseases as well as international terrorism. But the government has yet to repudiate the 1988 finding of the Drug Enforcement Administration's own administrative law judge, Francis Young, who concluded after extensive testimony that "marijuana in its natural form is one of the safest therapeutically active substances known to man."

Is marijuana a gateway drug? Yes, insofar as most Americans try marijuana before they try other illicit drugs. But no, insofar as the vast majority of Americans who have tried marijuana have never gone on to try other illegal drugs, much less get in trouble with them, and most have never even gone on to become regular or problem marijuana users. Trying to reduce heroin addiction by preventing marijuana use, it's been said, is like trying to reduce motorcycle fatalities by cracking down on bicycle riding. If marijuana did not exist, there's little reason to believe that there would be less drug abuse in the U.S.; indeed, its role would most likely be filled by a more dangerous substance.

Is marijuana dramatically more potent today? There's certainly a greater variety of high-quality marijuana available today than 30 years ago. But anyone who smoked marijuana in the 1970s and 1980s can recall smoking pot that was just as strong as anything available today. What's more, one needs to take only a few puffs of higher-potency pot to get the desired effect, so there's less wear and tear on the lungs.

Is marijuana addictive? Yes, it can be, in that some people use it to excess, in ways that are problematic for themselves and those around them, and find it hard to stop. But marijuana may well be the least addictive and least damaging of all commonly used psychoactive drugs, including many that are now legal. Most people who smoke marijuana never become dependent. Withdrawal symptoms pale compared with those from other drugs. No one has ever died from a marijuana overdose, which cannot be said of most other drugs. Marijuana is not associated with violent behavior and only minimally with reckless sexual behavior. And even heavy marijuana smokers smoke only a fraction of what cigarette addicts smoke. Lung cancers involving only marijuana are rare.

The government's most recent claim is that marijuana abuse accounts for more people entering treatment than any other illegal drug. That shouldn't be surprising, given that tens of millions of Americans smoke marijuana while only a few million use all other illicit drugs. But the claim is spurious nonetheless. Few Americans who enter "treatment" for marijuana are addicted. Fewer than one in five people entering drug treatment for marijuana do so voluntarily. More than half were referred by the criminal-justice system. They go because they got caught with a joint or failed a drug test at school or work (typically for having smoked marijuana days ago, not for being impaired), or because they were caught by a law-enforcement officer--and attending a marijuana "treatment" program is what's required to avoid expulsion, dismissal, or incarceration. Many traditional drug-treatment programs shamelessly participate in this charade to preserve a profitable and captive client stream.

Even those who recoil at the "nanny state" telling adults what they can or cannot sell to one another often make an exception when it comes to marijuana--to "protect the kids." This is a bad joke, as any teenager will attest. The criminalization of marijuana for adults has not prevented young people from having better access to marijuana than anyone else. Even as marijuana's popularity has waxed and waned since the 1970s, one statistic has remained constant: More than 80 percent of high-school students report it's easy to get. Meanwhile, the government's exaggerations and outright dishonesty easily backfire. For every teen who refrains from trying marijuana because it's illegal (for adults), another is tempted by its status as "forbidden fruit." Many respond to the lies about marijuana by disbelieving warnings about more dangerous drugs. So much for protecting the kids by criminalizing the adults.