EDITORIAL : RENO GOES TO COURT ATTORNEY GENERAL SPEAKS OUT ON AN IMPORTANT ISSUE.

ATTORNEY General Janet Reno made her debut Wednesday as an advocate before the Supreme Court, helping to present the government's case on a weighty constitutional question.

News reports noted that Reno was taking her turn at what has become a tradition - for the nation's top prosecutor to make at least one argument, in person, in the highest court in the land.

But her remarks, and the viewpoint she espoused, were not mere ritual. They were enormously important. And there's ample evidence of that, some of it written in the blood of police officers who have been killed in ``routine'' traffic stops.

This Supreme Court case examines the limits of police power when motorists are stopped for routine traffic violations, such as speeding or driving a vehicle with outdated license tags.

Nearly 20 years ago, the Supreme Court ruled that police have the authority to order drivers to get out of their cars during traffic stops. This new case asks whether police have the power to order passengers to exit the stopped vehicle, too.

Reno told the court that the expanded police power is necessary because traffic stops are dangerous and officers have to take reasonable actions for their own safety.

``They are vulnerable to attack, not just from the driver but from the passenger,'' she said. ``It's the person seated in the vehicle that creates the danger.''

Attorneys told the court that of the 708 police officers who were killed from 1985 to 1994, 97 were slain during traffic stops.

But lawyers for the other side contend that police safety must be weighed against personal privacy; giving police a blanket go-ahead would violate the Fourth Amendment's prohibition against unreasonable search and seizure.

This case arose from a Maryland traffic stop in which a state trooper ordered a passenger to step out. When he did so, some crack cocaine fell to the ground. He was prosecuted on drug charges, but state courts excluded the cocaine from evidence on grounds that the trooper's order violated the defendant's Fourth Amendment rights.

It seems to us that the high court can resolve this issue by sticking to the middle ground, and letting police order passengers out of a car after applying a test of reasonableness - in other words, for cause.

The Fourth Amendment prohibits unreasonable search and seizure, making it improper for police to automatically order everyone out of a stopped car, or to do it for no good reason.

But, as some of the justices observed, it's quite another thing if it's done on the basis of established standards - which police departments can adopt - outlining the circumstances in which such action would be advisable.

Such a sensible approach is a practical necessity, both to preserve Americans' civil liberties and to protect police, sheriff's deputies and highway patrol officers - if the courts truly believe they are entitled to a reasonable measure of safety while doing their jobs.