Marijuana laws - fair of unfair, rational or irrational, constitutional or unconstitutional?

That long-seething debate was the focal point last week of five days of testimony in a constitutional challenge of the federal ban on marijuana possession. The challenge could have far-reaching implication for the 16.2 million Americans who regularly (and illegally) smoke the intoxicant, according to federal estimates.

Half a dozen doctors and psychiatrists, an Episcopalian canon and a retired penologist testified before U.S. District Court Judge Aubrey Robinson.

A ruling in the elaborate, four-year-old case is not expected until at least late this fall.

The National Organization for the Reform of Marijuana Laws (NORML), which brought the challenge, contends marijuana is largely harmless and that the law violates the constitutional right to privacy of adults who want to possess small amounts of the drug for personal, noncommercial use.

NORML also contends the law is applied disproportionately against minorities and that prisons are illequipped to handle convicted marijuana users in violation of constitutional provisions guaranteeing equal protection under the law and prohibiting cruel and unusual punishment.

The Justice Department, principal defendant in the case, contends marijuana intoxication and disorientation cause short term hazards and the rapidly growing popularity of marijuana requires more medical and psychological research of its long term effects before relaxation of the laws should be considered.

Facing Robinson and two other judges assigned to consider the case is this fundamental question: did Congress enact the marijuana ban without sufficient evidence of its harmfulness and in such an irrational and arbitrary manner as to justify judicial intervention?

"That's what this case is all about," "Robinson said during the hearing last week.

Several state courts, including those of Alaska, Michigan and Illinois, have ruled marijuana possession laws unconstitutional on grounds similar to those in the case here. But NORML attorneys view their challenge of the federal law as a crucial element in NORML's decade-long campaign to decriminalize marijuana throughout the nation.

The maximum penalty for the first offense of marijuana possession under the federal law is a year in prison and a $5,000 fine. Maximum penalty for subsequent offenses is two years and $10,000.

The National Institute on Drug Abuse (NIDA) estimates there are 16.2 million regular users of marijuana in the United States and that 16 million people have tried it at least once.

One significant element in the court cases here is that the federal government appears to have softened its view on marijuana since the case was instituted in 1973. Flat opposition to marijuana as a dangerous drug has to some extent given way to a cautious let's-do-more-research position.

NORML for its part has muted some of its enthusiasm about marijuana, acknowledging there is little research on long term effects of heavy marijuana use and that some people with pre-existing heart conditions and other medical problems should not smoke at all.

"It's remarkable how similar both the government's and our positions have come in terms of legal perspectives and what the witnesses said in court," said NORML chief attorney Peter Meyers in an interview after the hearing.

At the hearing, the Rev. Walter D. Dennis, canon of the Episcopal Archdioceses of New York, testified for NORML that marijuana and other drug control laws grew out of an anti-immigrant attitude in late 19th century America and was directed largely at "darker skinned people . . . the Chinese and their opium, the blacks and their cocaine, the Indians and their peyote, the Mexican-Americans and their marijuana."

James Murphy, a retired federal prison warden and not a consultant on penology, testified that imprisoning a marijuana user is largely destructive, interrupting his job, dislocating him socially, traumatizing him by exposure to hardened criminals and serving no deterrent effect.

"I can't see that (marijuana) misdemeanants are treated any differently then other misdemeanants," snapped Robinson.

"If that's the thread you want to hang your arguments on, I think it's very remote," he said.

One of the few areas of sharp disagreement between NORML and the Justice Department was the question of marijuana intoxication and high-way safety.

"We now know that marijuana intoxication poses a significant threat to highway safety in much the same way that alcohol does," said Robert L. DuPont, director of the National Institute on Drug Abuse, in a report submitted in the case by the Justice Department.

But Lester Grinspoon, a Harvard Medical School professor, contended in testimony for NORML that marijuana users are uniquely "aware of the risks of driving while stoned."

Unlike a driver drunk on alcohol, he said, "a marijuana user is more likely to be very cautious, to have both hands on the wheel and to be very conscious of his condition."

Robinson is one of three judges on a special panel designated to hear the NORML challenge. The other two judges - Barrington Parker of the U.S. District Court and Edward Tamm of the U.S. Court of Appeals here - did not attend last week's hearing. They will read a transcript of the testimony, however, and join Robinson in hearing final arguments by attorneys in the casethis fall. The panel's ruling will be directly appealable to the Supreme Court.