LOS ANGELES
The Supreme Court's ruling Thursday that it is unconstitutional to execute mentally retarded people was good news for opponents of the death penalty. They hailed it as a landmark decision that signals a fundamental shift in the court's stance toward capital punishment.
Their celebration is understandable. But it will almost certainly be temporary. History shows that public opposition to capital punishment vacillates over time. And though the Supreme Court is less responsive to shifts in popular opinion than state lawmakers, Congress or the president, it is not immune to them.
In the past few years, opponents of the death penalty have won several victories. The governors of Illinois and Maryland have declared moratoriums on conducting executions until flaws in those states' criminal justice systems are eliminated. A federal district judge in New York has announced that he intends to find the federal death penalty statute unconstitutional on the ground that innocent people are too likely to be executed. Meanwhile, the annual number of executions has been declining, from 98 in 1999 to 66 in 2001.
But throughout American history, support for the death penalty has risen and fallen with the times. In periods when Americans have tended to think of crime as the product of the criminal's free will, the criminal justice system tilts toward retribution, and capital punishment has grown more popular. In periods when they have paid more attention to causes other than the criminal's free will — the criminal's social context, for example — the system has emphasized rehabilitation, and the popularity of the death penalty has waned.
The past 30 years were a period of strong support for capital punishment, as part of a trend toward retribution in criminal sentencing. (This trend is also evident in other sentencing measures like "three strikes" laws.) For the past 250 years, however, such periods have always been followed by times of growing opposition to the death penalty.
There is certainly nothing inexorable about this pattern. But we may well be seeing the beginning of the next long swing away from the death penalty. In the past, the early signs have been the abolition of capital punishment for those criminals for whom the death penalty seemed disproportionately severe. In the 18th century minor criminals like counterfeiters and horse-stealers were the first to be spared the death penalty; in the 19th century, it was rapists and robbers who were spared. Today it's the mentally retarded, and tomorrow it may be 16- and 17-year-olds, who are still eligible to be executed in some states.
In the relatively short time that the Supreme Court has considered capital punishment to raise constitutional questions, it has followed the oscillations of public opinion. Furman vs. Georgia, the 1972 case that found existing death-sentencing schemes unconstitutional, was decided near the peak of opposition to the death penalty, as measured by public opinion polls. For the next 30 years, as capital punishment gained support, the court gradually watered down the restrictions against capital punishment in the Furman case. And now, just when that support is showing signs of weakening, the court has imposed the first important new constitutional restriction on capital sentencing in many years.
There is nothing unusual or improper about this link between public opinion and the court's decisions. The justices are chosen by an elected president and confirmed by an elected Senate, of course. And just as important, they are not hermits; they are influenced by the same trends in thought that influence us all.
Unlike legislators or executives, however, judges cannot simply rewrite, repeal or veto laws they do not like. The Supreme Court must place each ruling it makes in the context of its past decisions; it must follow precedent. But it is not as difficult for the court to change course as is commonly thought. Indeed, its conclusion that executing mentally retarded offenders now is cruel and unusual punishment directly contradicts a decision it issued only 13 years ago.
Claims of cruel and unusual punishment have long been evaluated according to "evolving standards of decency." In such cases, the court must ask what those standards are and, as it acknowledged in its decision Thursday, the ongoing public debate "informs our answer."
This kind of analysis by its very nature calls on the court to consider broadly held public views. If in the future public opinion evolves in favor of executing retarded people, states will likely adopt definitions of mental retardation that are more restrictive, encompassing fewer and fewer defendants. It would not be surprising then to see the court approve those restrictions until the principle stated in this week's case gets narrowed, perhaps into irrelevance.
That is, until the next swing comes.
Stuart Banner is a law professor at U.C.L.A. and author of "The Death Penalty: An American History.''
