FRIDAY SHOULD have been the day that the Justice Department responded to a petition for the Supreme Court to review a lower court holding that the famed case of Miranda v. Arizona is no longer good law. Yet for the second time, the department has received an extension from the court. The delay only heightens the question of how the department will handle what has become a very sticky situation.

Miranda, most famous of all criminal procedure decisions, requires that suspects be read their constitutional rights before being interrogated. In the aftermath of the 1966 decision, Congress passed a law designed to reverse it. The statute makes admissible any confession that was voluntarily given -- effectively restoring the pre-Miranda standard. The Justice Department has at times flirted with the law, but administrations of both parties have generally not invoked it on the theory that it was plainly at odds with the high court's ruling and, therefore, unconstitutional. In 1997, the Justice Department announced that it would no longer invoke the law before lower courts, because only the Supreme Court could reconsider the Miranda holding.

Now, however, the statute is before the Supreme Court, thanks to a truly abominable decision by the 4th Circuit Court of Appeals. A split panel ruled that a confession could be admitted under the statute, which it held -- egged on by conservative activists -- to be constitutional despite the fact that the department had declined to invoke it and even though the defendant appears to have been advised of his rights in the first place.

The defendant, Charles Dickerson, has asked the Supreme Court to hear the case, putting the Justice Department in the unenviable position of having to respond in a way that simultaneously permits his prosecution and does no violence to firmly established law. That's a tall order, especially since the solicitor general is typically obliged to defend an act of Congress when a reasonable argument can be made for its constitutionality.

Yet it would be deeply wrong for the Justice Department to urge the court to reverse Miranda. The decision has both protected defendants and offered law enforcement clear rules under which to operate. Respect for precedent alone should protect an opinion that has so infused our legal culture as to be quoted on every police show on television. Moreover, there is something grotesque about the idea of the United States reconsidering its views on a 33-year-old decision, one that doesn't really adversely affect law enforcement, simply because a lower court, in overtly political tones and in response to a brief from a non-party, decides to try to overrule the Supreme Court.

The right course is for the Justice Department to argue that the statute is invalid, that Miranda is good law, and that Mr. Dickerson's confession complied with its requirements.