How can we end the death penalty in the United States? Every so often, one capital case receives wide attention and makes a public spectacle of the American machinery of death. Last week, it was the controversy over Troy Davis, who was executed in Georgia after years of impassioned argument, organizing, and litigation.

I honor those who worked so hard to save Davis's life because they forced the nation to deal with all the uncertainties, imperfections, and, in some instances, brutalities of the criminal-justice system. Yet after all the tears are shed and after the last candlelight vigil ends with a prayer, the repeal of capital punishment is still a political question. Can the politics of this question change? The answer is plainly yes.

It's hard to imagine now, but in 1966, more Americans opposed the death penalty than supported it -- by 47 percent to 42 percent. But the crime wave that began in the late '60s and the sense that the criminal-justice system was untrustworthy sent support for capital punishment soaring. By 1994, 80 percent of Americans said they favored the death penalty and only 16 percent were opposed.

Since then, the numbers have softened slightly. Over the past decade, the proportion of Americans declaring themselves against capital punishment has bumped around between 25 percent and 32 percent. The mild resurgence of opposition -- caused by a decline in violent crime and by investigations raising doubts about the guilt of some prisoners on death row -- has opened up political space for action.

Liberals are not going to be the ones who lead this fight. Too many Democratic politicians remember how the death penalty was used in campaigns during the 1980s and '90s, notably by George H. W. Bush against Michael Dukakis in 1988. They're still petrified of looking "soft" on crime.

Moreover, winning this battle will require converting Americans who are not liberals. The good news is that many citizens are open to persuasion. Gallup's polling shows that support for capital punishment drops sharply when respondents are offered the alternative of "life imprisonment, with absolutely no possibility of parole." When Gallup presented this option in its 2010 survey, only 49 percent still chose the death penalty; 46 percent preferred life without parole.

And a survey last year for the Death Penalty Information Center by Lake Research Partners showed that if a variety of alternatives were offered to respondents (including life without parole plus restitution to victims' families), hard support for the death penalty could be driven down to 33 percent. If a majority is open to persuasion, the best persuaders will be conservatives -- particularly the overlapping groups of religious conservatives and opponents of abortion -- who have moral objections to the state-sanctioned taking of life or see the grave moral hazard involved in the risk of executing an innocent person.

There have always been conservatives who opposed the death penalty, but perhaps now their voices will be heard. In Ohio this summer, state Rep. Terry Blair, a Republican and a staunch foe of abortion, declared flatly: "I don't think we have any business in taking another person's life, even for what we call a legal purpose or what we might refer to as a justified purpose."

Last week, Don Heller, who wrote the 1978 ballot initiative that reinstated the death penalty in California, explained in the Los Angeles Daily News why he had changed his mind. "Life without parole protects public safety better than a death sentence," he wrote. "It's a lot cheaper, it keeps dangerous men and women locked up forever, and mistakes can be fixed."

The most moving testimony against Troy Davis' execution came from a group of former corrections officials who, as they wrote, "have had direct involvement in executions."

"No one has the right to ask a public servant to take on a lifelong sentence of nagging doubt, and for some of us, shame and guilt," they said. "Should our justice system be causing so much harm to so many people when there is an alternative?"

We live in an unreasonable time when political ideology has built a thick wall that blocks us from acknowledging that some of the choices we face are tragic. Perhaps we can make an exception in this case and have a quiet conversation about whether our death-penalty system really speaks for our best selves. And I thank those conservatives, right-to-lifers, libertarians, and prison officials who, more than anyone else, might make such a dialogue possible. 

(c) 2011, Washington Post Writers Group

Related: A Slow Death, by William Bole
Justice or Vengeance, by Cathleen Kaveny