Curtailing a state prisoner’s federal rights to challenge his incarceration–known as “habeas corpus relief”–has become an obsession for Rehnquist. Since he became chief in 1986, he has campaigned in opinions and speeches for the change, which would affect capital cases most prominently. Habeas claims, he argues, clog the federal courts, foment disrespect for the states and delay just punishment for the condemned. As far back as 1981, when he was still an associate justice, Rehnquist belittled the “arcane niceties” of death-penalty law. In recent years, Rehnquist has lobbied Congress to restrict-and in some cases bar altogether-claims if they’ve been presented in state court.

But Congress never acted. So Rehnquist and his conservative colleagues set out to accomplish by judicial fiat what had eluded them legislatively. In a string of decisions, the justices slammed the door on inmates looking to get into federal court. If such procedural rules as filing deadlines were not strictly complied with–if the lawyer made a valid claim one day late–the inmates were out of luck. Last week, in a 54 decision, the justices went further: even if all the rules were followed, the federal courts still were not obliged to hear a case unless an inmate could show a good reason why a claim had not been raised earlier. In its decision, the court said a lawyer’s blunder wasn’t a good enough reason.

This was too much even for Justice Sandra Day O’Connor, who had joined the court’s earlier cases cutting back on habeas claims. By statute, Congress had permitted prisoners to seek federal vindication of their rights. Last week’s decision, she wrote, “cannot be reconciled” with Congress’s clear intent.

The usual question about the Rehnquist court is, how conservative has it become? Perhaps the more apt query is, how radical? Again, the nation has an activist court.