WASHINGTON - When Justice Sandra Day O'Connor told a group of Minnesota lawyers recently that she was worried about the administration of the death penalty and the possibility of executing innocent defendants, opponents of capital punishment were more than a little surprised.
Since being appointed to the Supreme Court in 1981, O'Connor has voted to speed the pace of executions and limit the ability of death row inmates to appeal their convictions and sentences. She has also rejected claims that the Constitution forbids the execution of the mentally retarded and defendants as young as 16.
More than just a surprise, however, O'Connor's statement was the latest and perhaps clearest sign of how sharply the debate over the death penalty has shifted in recent years.
In the early to mid-1990s, with violent crime hitting record levels and public concern about safety rising, polls showed that 75 percent to 80 percent of Americans supported the death penalty. It was the highest level of support since polling began in the 1930s, and few experts predicted that it would drop any time soon.
But that is precisely what has happened over the past two or three years. Though a majority of Americans still endorse capital punishment, polls show that the level of support has fallen to between 60 percent and 65 percent, the lowest point since the mid-1970s.
"I think we're at an important moment of reconsideration of the death penalty," said Austin Sarat, an Amherst College professor who recently published a book on the subject. "Even though 63 [percent] or 65 percent of people say they're in favor of capital punishment, support is weakening when people are presented with realistic alternatives."
The substance of the debate has also changed. Whereas discussion used to revolve around moral issues - such as whether the state should ever take a life - it now centers on pragmatic questions: Is the death penalty being unfairly administered? Are innocent people being sentenced to death?
And these questions are being asked not only by liberals but also by prominent conservatives. In her speech to the Minnesota group, O'Connor noted that more than 90 death row inmates nationwide have been exonerated by new evidence since 1973 and that many capital defendants are poorly represented at trial.
"The system may well be allowing some innocent defendants to be executed," she said.
Outspoken conservatives such as Pat Robertson, Oliver L. North and George Will have expressed similar concerns. Indeed, polls show that as many as two-thirds of Americans support a moratorium on executions until questions about the fairness and integrity of the way the death penalty is administered can be resolved.
These changes in public opinion have already had tangible effects. Last year, Illinois Gov. George Ryan, a Republican, halted executions in his state after it was reported that 13 death row inmates there had been exonerated since 1977.
This year, Arizona, Connecticut, Florida and Missouri banned executions of the mentally retarded, bringing to 17 the number of states with such policies. And many of the 38 states with the death penalty are considering or have approved legislation to provide greater protection for those accused of capital crimes.
Meanwhile, a bill pending in Congress would require states to provide qualified and experienced attorneys to all defendants facing the death penalty and would improve access to DNA testing.
Not all efforts to reform or eliminate the death penalty have succeeded. A proposed moratorium in Maryland stalled in the Senate this year. And bills that would have temporarily halted executions in New Hampshire and Nebraska were vetoed by the governors of those states.
But opponents of the death penalty are more optimistic than they have been in years. They say the shift in public opinion could lead to serious reforms and possibly the elimination of capital punishment.
The story of how public sentiment on such an emotional issue has evolved over the past few years is a striking one. And it is a development that experts are still trying to explain.
Many point to the sharp drop in violent crime since the mid-1990s. They note that there has historically been a close correlation between safety concerns and support for the death penalty.
"Some part of the support for the death penalty comes from fear and vulnerability," says Robert Blecker, a New York Law School professor who supports capital punishment as a legitimate means of retribution. "And to the extent we fear less, we're less likely to support it."
Experts also point to the rising condemnation of capital punishment by religious leaders, particularly Pope John Paul II, who in 1999 persuaded the governor of Missouri to spare the life of a death row inmate.