The Supreme Court set off some predictable howling with its two opinions of March 21 on drug testing, but critics were howling before they were hurt. There is much less here than meets the eye.

Once again, as in so many of these Fourth Amendment cases, the court had to construe a single word. The amendment does not forbid all searches of our persons, houses, papers and effects. It forbids only those searches that are "unreasonable." The question in both cases was whether the proposed tests were reasonable; the court ruled that they are.Case No. 1 was much the easier of the two. It involved mandatory blood and urine tests of railway crew members who are involved in certain train accidents. By a vote of 7-2, the court held that such tests are acceptable. The court balanced the workers' rights against "the surpassing safety interests" of the traveling public, and came down on the side of the public interest.

Justice Thurgood Marshall, joined by Justice William Brennan, objected that in the wake of an accident, federal inspectors may demand the blood and urine samples without first obtaining a warrant, but on this point the majority clearly had the better argument. In the chaotic few hours after a train wreck, it simply is not possible to find a neutral magistrate and to establish probable cause for searching named employees and "particularly describing the things to be seized."

Case No. 2 was tougher. Here the U.S. Customs Service seeks mandatory urinalysis tests for three classes of employees - those directly engaged in drug interdiction, those with authority to carry firearms and those with access to certain classified material. The court voted 5-4 to approve tests for the first two groups but balked at tests for the third group. The Fifth Circuit Court of Appeals was ordered to reconsider this aspect of the case.

Here, too, the majority balanced private rights against the public interest, and here too the majority found it "impractical" to require search warrants based upon probable cause. Customs agents stand in the front line of the nation's war against drug smugglers. The government has a "compelling interest" in ensuring that agents are physically fit and have unimpeachable integrity and judgment.

Justice Antonin Scalia filed an impassioned dissent. He is by far the best writer on the court.

But in the case of the customs agents, Scalia got swept away on the waves of his own eloquence. He described the urine tests as "a kind of immolation of privacy and human dignity." He scoffed at the justification for such searches. He leaped into speculation that if drug tests may be required of customs agents who carry firearms, similar tests may be required of everyone whose work may endanger others, such as automobile drivers. Then Scalia cartwheeled into an awful vision of a future in which virtually no one in public or in private life would be safe from the drug testers with their little sampling bottles. Simmer down, Scalia!

The key point, in my own view, is not at all complex. I would argue that while each of us has a constitutional right to be protected against unreasonable searches, none of us has a constitutional right to be a gun-packing customs agent on the front line of drug interdiction. The tests are a condition of employment, in exactly the same fashion that checks for firearms are a condition of airline travel. We have a right to fly; but we have no right to fly without first passing through a metal detector. I would make the further argument that urinalysis, under the carefully safeguarded conditions of the Customs Service, is a very minimal intrusion upon one's "expectations of privacy."

Let us be reasonable. The traveling public has a right to be protected against drunken engineers. The government has a right to a drug-free workplace in highly sensitive areas. To the extent that these tests promote those valid ends, they impose no constitutional harm.