Johnson had been represented at his trial by one of the most notoriously inept death penalty lawyers in history. The lawyer fell asleep in numerous trials, including Johnson's. He was eventually no longer permitted to represent capital murder defendants. Johnson's co-defendant pleaded guilty, and had long since been released from prison by the time Johnson's execution date rolled around.

Johnson grew up in prison. He became religious and repentant. He did not falsely proclaim his innocence or blame anyone other than himself for his mistakes, which he acknowledged to be serious and perhaps unforgivable. At the same time, in his years in prison, he had no significant disciplinary violations. He worked in prison. He crafted religiously-inspired art. He got his high school equivalency diploma.

I thought of Johnson on the day that President Bush commuted the prison sentence of I. Lewis Libby, Vice President Dick Cheney's former chief of staff, a man who was convicted of lying to a grand jury — that is, a man who was convicted of perjury. President Bush went to the White House saying he was going to bring integrity back to the Oval Office, a reference to President Clinton, who had been impeached for lying to a grand jury, the same as Libby's crime. President Bush got elected despite charges that he had used his father's connections to avoid service in Vietnam, the place where my client, Carl Johnson, found heroin.

In Texas, the governor cannot commute a death row inmate's sentence without approval of the Board of Pardons and Parole. The governor still wields great power, however, because the governor appoints the members of the board, and they take their cues from him. When Gov. Bush wanted to commute the death sentence of Henry Lee Lucas, a man believed by some law enforcement officers to have been a serial killer but who probably did not murder the woman he was sent to death row for killing, he let it be known, and the board accommodated his wishes, recommending a commutation, which Governor Bush signed in 1998.

I asked then-Gov. Bush to grant my client a 30-day reprieve, with the idea that he could thereby signal to the board his belief that Johnson's death sentence should be commuted to life. He denied my request, as he denied the other 56 requests that were made of him by lawyers representing death row inmates. Some of these inmates were mentally retarded. Some were juveniles when they committed their crimes. Gov. Bush always gave the same explanation: that the inmates had had full access to the legal system. He gave that same reason when he turned down a reprieve request made by the lawyers representing Karla Faye Tucker, whose reformation on death row was legendary, and when he rejected the reprieve request made by lawyers representing Gary Graham, who was probably innocent.

My client, Carl Johnson, committed the worst crime that can be committed against another human being: He killed someone. And Lewis Libby committed the crime that is most injurious to our criminal justice system: He lied. Unlike my client, Libby, who was convicted by a jury of his peers despite being represented by the best lawyers that money can buy, has never shown any public sign of remorse. Nevertheless, despite all that, President Bush did not exceed his authority in commuting Lewis Libby's prison sentence. The Constitution gives him the power to do what he did. But it is possible for actions to be lawful and simultaneously in conflict with other constitutional principles. Last week's pardon deeply offends the constitutional value of equality, the idea that all citizens stand equal before the law.

Lewis Libby had something in common with the other people George Bush has pardoned, and with people President Clinton pardoned as well: He is rich and powerful, and he has rich and powerful connections. People do not get pardons because they are mentally retarded, or because they were young when they committed their crime, or because they had terrible lawyers, or because they have reformed, or even because they are innocent. They get them because they have friends in high places. That might not be illegal, but it's still wrong, and a president who issues pardons and commutations on that basis has not done very much at all to bring integrity to the Oval Office.

These cases have something in common: they pivot on the question of innocence. For too many years now, though, death penalty opponents have seized on the nightmare of executing an innocent man as a tactic to erode support for capital punishment in America.

Innocence is a distraction. Most people on death row are like Roger Coleman, not Paul House, which is to say that most people on death row did what the state said they did. But that does not mean they should be executed.

Focusing on innocence forces abolitionists into silence when a cause célèbre turns out to be guilty. When the DNA testing ordered by Gov. Mark Warner of Virginia proved that Mr. Coleman was a murderer, and a good liar besides, abolitionists wrung their hands about how to respond. They seemed sorry that he had been guilty after all.

I, too, am a death penalty opponent, but I was happy to learn that Mr. Coleman was a murderer. I was happy that the prosecutors would not have to live with the guilt of knowing that they sent an innocent man to death row.

The day before the DNA results were reported in the Coleman case last January, the Supreme Court heard oral arguments in the Paul House case. In Mr. House's case, the DNA testing has already been done, and it tends to suggest that he is indeed innocent. During oral arguments, however, Justice Antonin Scalia (who was one of the three dissenters when the court decided the case this week) argued that disputes over factual findings in a case can't be endlessly rehashed.

He is certainly right about that. As Justice Scalia has said elsewhere, of course we are going to execute innocent people if we have the death penalty. The criminal justice system is made up of human beings, and fallible beings make mistakes.

But perhaps that is a price society is willing to pay. If the death penalty is worth having, it might still be worth having, despite the occasional loss of innocent life. Paul House might be innocent, but how long will we keep death row inmates alive, waiting to find out?

In Mr. Coleman's case, the Virginia Supreme Court did not address the arguments that he had raised in his appeal, because his lawyer had filed the papers one day late. When the case got to the United States Supreme Court, the court, in an opinion by Justice Sandra Day O'Connor, began its analysis by saying, "This is a case about federalism."

The case did have something to do with the relationship between the Supreme Court and Virginia's highest court. But is that what the case was really about? Mr. Coleman was saying that his trial lawyer had been incompetent, and that the Virginia courts were refusing to address the question of whether his trial lawyer had been incompetent because his appellate lawyer had filed the appeal a day late.

Federalism might be a plot line in this story, but it hardly seems to be the major issue. When the Supreme Court brushed aside Mr. Coleman's appeal 15 years ago, the justices said that a death row inmate cannot complain when his lawyer misses a filing deadline, because the lawyer is the agent of the client, and clients are responsible for the failings of their agents.

As a result of this syllogism, my client Johnny Joe Martinez was executed in 2002, because his court-appointed appellate lawyer neglected to file a proper appeal — a mistake he freely admitted to, attributing it to inexperience. When the Martinez case reached the federal courts, those courts, invoking the Coleman decision, said too bad for Mr. Martinez; the mistake of his lawyer was attributable to him. I could go on with other examples.

Of the 50 or so death row inmates I have represented, I have serious doubts about the guilt of three or four — that is, 6 to 8 percent, about what scholars estimate to be the percentage of innocent people on death row.

In 98 percent of the cases, however, in 49 out of 50, there were appalling violations of legal principles: prosecutors struck jurors based on their race; the police hid or manufactured evidence; prosecutors reached secret deals with jailhouse snitches; lab analysts misrepresented forensic results. Most of the cases do not involve bogus claims of innocence, like the one that swirled for 15 years around Roger Coleman, but the government corruption that the federal courts overlook so that the states can go about their business of executing.

The House case will make it hard for abolitionists to shift their focus from the question of innocence, but that is what they ought to do. They ought to focus on the far more pervasive problem: that the machinery of death in America is lawless, and in carrying out death sentences, we violate our legal principles nearly all of the time.