The number of cases the court decided with signed opinions last term, 69, was the lowest since 1953 and fewer than half the number the court was deciding as recently as the mid-1980s. And aside from the school integration and global warming cases the court heard last week, along with the terrorism-related cases it has decided in the last few years, relatively few of the cases it is deciding speak to the core of the country’s concerns.

The reasons for the decline all grow out of forces building for decades. The federal government has been losing fewer cases in the lower courts and so has less reason to appeal. As Congress enacts fewer laws, the justices have fewer statutes to interpret. And justices who think they might end up on the losing side of an important case might vote not to take it.

In a divided court, in a divided country, the court’s reduced role is perhaps not surprising, nor is it necessarily a bad thing. “In the post-Bush v. Gore era, the court may be concerned about taking the wrong case and making an unpopular decision,” said Frederick Schauer, a professor at the John F. Kennedy School of Government at Harvard, in an interview.

Professor Schauer argued in a recent and much-discussed Harvard Law Review article that the court’s work “had only minimal direct engagement with the central issues of the nation’s public and policy agenda.” In an interview, he said, “I think they like being under the radar.”

In private conversations, the justices themselves insist that nothing so profound is going on, but rather seem mystified at what they perceive as a paucity of cases that meet the court’s standard criteria. The most important of those criteria is whether a case raises a question that has produced conflicting decisions among the lower federal courts.