Even if marijuana were dangerous enough to justify criminalizing its uncontrolled use, it would still be preposterous to ban its use as a medical treatment, in a nation where endless assortments of far more dangerous drugs are prescribed by the millions every day.

Another chapter in that disgraceful history was written this week, when the Supreme Court refused to overturn a federal law ordering the national government to ignore state laws that allow doctors to prescribe marijuana for their patients.

The six justices who voted to uphold the law did so on the basis of this argument: Congress has the power to regulate interstate commerce. If states make it legal for individuals or organizations to cultivate marijuana for medicinal purposes, some of the drug may end up on the black market.

Once it's in the stream of commerce, there's no way to ensure that it won't cross state lines. Hence the federal government has the authority to enforce federal laws that make growing a single marijuana plant in one's own house, for personal medical use under the supervision of a doctor, a federal crime.

In the Grip of Reefer Madness

This ruling comes from the same court that decided not too long ago that the federal government doesn't have the power to make it a crime to possess a handgun in a school zone, because such a law doesn't affect interstate commerce.

Of course another distinction between these two cases is that no one was hurt by a handgun in the United States last year, while marijuana kills 410,000 people annually. (Following precedents established recently by the Centers for Disease Control and Prevention Director Julie Gerberding, I'm simply fabricating whatever statistics will support insane public policies).

Nothing captures the extent to which we are still in the grip of reefer madness than this sentence from Justice Antonin Scalia's concurrence: "Congress has undertaken to extinguish the interstate market in Schedule I controlled substances, including marijuana. The Commerce Clause unquestionably permits this."

Sometimes it's important to step back from ordinary-sounding statements, so as to appreciate how flat-out crazy they really are.

Alice in Wonderland Universe

First, consider what a gigantic edifice of lies must be maintained for government officials to continue to classify marijuana as a Schedule I drug. A Schedule I drug must have a high potential for abuse, no recognized medical use, and no safe use under medical supervision.

Marijuana does not have a high potential for abuse in comparison to substances such as alcohol and tobacco, it has a number of recognized medical uses, and it's almost perfectly safe when used under medical supervision. These are not opinions; they are facts.

These facts are worth repeating, because it's always worth pointing out that the federal government is telling lies to the public, and that politicians who traffic in these lies should be called to account for doing so.

Second, let us ponder for a moment the Alice in Wonderland universe in which "Congress has undertaken to extinguish the interstate market in marijuana." Despite ferocious government repression, millions of Americans continue to use marijuana on a regular basis.

The only risks such use poses for the vast majority of these people are the risks inherent in breaking laws -- stupid and immoral laws that will continue to be treated with the contempt they deserve.

Even if marijuana were dangerous enough to justify criminalizing its uncontrolled use, it would still be preposterous to ban its use as a medical treatment, in a nation where endless assortments of far more dangerous drugs are prescribed by the millions every day.

In the long run, nothing undercuts respect for legal authority more than the kind of moral cowardice that allows laws of this sort to be enacted and enforced.

Paul Campos is a professor of law at the University of Colorado. He can be reached at paul.campos@colorado.edu.