MAYBE YOU don't have the right to remain silent. Or to have an attorney present during police questioning. And maybe police can aggressively press you to talk even if you're gravely wounded or on your death bed.

Of course, in nondemocratic nations, that's standard operating procedure. Police are in charge -- and citizens are at their mercy.

But for the second time in three years, the U.S. Supreme Court is considering a challenge to its landmark Miranda decision, which protects people in this country from unbridled coercive interrogation by the police. Make no mistake -- if the court sides with Oxnard, Calif., police in this case, the gulf between American justice and foreign tyranny will have closed significantly.

Miranda has its roots in two constitutional amendments -- the Fifth, which secures the right to avoid self-incrimination, and the 14th, which guarantees due process under the law. When it was decided in 1966, then-Chief Justice Earl Warren said the Miranda limitations had to extend to police because their questioning of citizens was, by nature, coercive.

But for years, others have argued that these rights have to do with court proceedings, not police interrogations. Current Chief Justice William H. Rehnquist even wrote in a 1990 decision that the right against self-incrimination only comes into play at trial; constitutional violations can only occur in court, he said.

That's the basis of the current challenge, too, which is why many believe this case may find sympathy with the court. Lawyers for the officers in the case argue that their clients were free to interrogate Oliverio Martinez as much as they wanted, so long as they didn't use what they got from him at trial. The only restraint, they say, should prevent torture or denial of food and water.

Their logic flunks the test of common sense, given the growing body of evidence that even legal police interrogations sometimes go too far. But it also defies the facts of their clients' case: The Oxnard officers had shot Mr. Martinez five times in the eyes, spine and legs before they began to question him. As he screamed in agony in an ambulance and an emergency room, they pressed him to confess to trying to kill one of the officers. (In fact, he was ultimately not charged with any crime -- and wound up suing the police for illegal arrest, excessive force and coercive interrogation.)

It's hard to imagine any circumstances under which that kind of police behavior should be sanctioned.

Of course, this case will be heard against the backdrop of the government's new obsession with "homeland security," and some experts believe the challenges to Miranda ultimately boil down to authorities' desire to be able to more aggressively question terrorism suspects.

But like many of the assaults on Americans' civil rights in the name of security, this one is a gross over-reach. Miranda is ingrained in the bedrock of U.S. civil liberties, and an important legal distinction between this country and others. Reversing it won't make Americans safer -- quite the contrary.