Samuel Johnson famously remarked, “When a man knows he is to be hanged in a fortnight, it concentrates his mind wonderfully.” But precisely because it so concentrates the public mind, capital punishment has distorted the criminal justice system. Over the past 40 years, while the Supreme Court has been “tinker[ing] with the machinery of death,” in Justice Harry Blackmun’s haunting phrase, other components of the system have broken down untended.

In 1972, by a vote of 5-4, the Supreme Court struck down all existing capital punishment statutes in the United States. While three justices were prepared to hold the death penalty unconstitutional under all circumstances, two others focused on the fact that the existing statutes led to arbitrary decisions that followed no legal standards. As Justice Potter Stewart put it, capital punishment violated the cruel and unusual punishment clause of the Eighth Amendment because being sentenced to death was like “being struck by lightning.”

Many states responded by enacting new capital punishment statutes that purported to formalize decision making. In 1976 the Supreme Court upheld several of these efforts, pointing to key procedural safeguards, such as the creation of a separate penalty phase to determine whether the defendant deserves to die. In this penalty phase, defense counsel can present a broad range of mitigating evidence that may diminish the defendant’s culpability or incline the judge or jury to mercy.

But too often the formal safeguards that reassured the Court have proved illusory in practice. Underfunded, untrained, or outright incompetent lawyers often fail to provide their clients even minimally adequate representation. A 1990 study by the National Law Journal found that a quarter of the inmates then on Kentucky’s death row had been represented at their trials by lawyers who were later disbarred, suspended from practice, or convicted of crimes. A capital defendant in Georgia was assigned a lawyer who knew the name of only a single criminal law opinion decided by any court.

And however unwilling the Supreme Court has been to ensure that capital defendants receive truly competent representation—its interpretation of the Sixth Amendment’s guarantee of effective assistance of counsel sets the bar so low that courts have upheld convictions in cases where the lawyer was actually asleep during part of the proceedings—it has been even less willing to police systemic unfairness in who is targeted for the most awesome punishment. In McClesky v. Kemp (1987) the Court rejected powerful statistical evidence showing that the death penalty in Georgia was infected by racial disparities: black defendants convicted of killing white victims were far more likely to be sentenced to death than any other group. Justice Lewis Powell’s opinion was unusually candid in explaining why the Court could not accept McClesky’s claim: “Taken to its logical conclusion,” Powell wrote, McClesky’s position “throws into serious question the principles that underlie our entire criminal justice system.” Racial disparities marbled the criminal justice system, so they had to be ignored.

Because the Court and Congress convinced themselves that death row inmates were dragging out the process of post-conviction appeals, they have dramatically restricted the ability of all defendants to seek habeas corpus, the primary vehicle for bringing constitutional challenges against state court convictions. The provisions of the Antiterrorism and Effective Death Penalty Act of 1996 (AEDPA) create a procedural obstacle course that prevents federal courts from addressing the merits of a defendant’s constitutional claims. For example, in the first week of the current Supreme Court term, the Court heard oral argument in the case of Cory Maples, a death row inmate in Alabama who so far has been unable to get the federal courts to hear his claim that his trial lawyer was ineffective at his sentencing. The reason? The volunteer lawyers who later represented him moved on to new jobs, and when the state court ruled against his claim, there was no one at their former law firm to receive the letter announcing the decision. The letter was stamped “Return to Sender,” and the deadline for appeal passed before anyone noticed. As a result, federal courts accepted the state’s argument that Maples had “defaulted” his claims.

Ineffective trial lawyers, inconclusive evidence, inconsistent testimony, and impenetrable procedural thickets are not unique to capital cases.

A fortnight before, the Court stayed the execution of Duane Buck, whose death sentence Texas seeks to insulate from federal review despite the fact that, under questioning from a prosecutor, a psychologist told the jury that being black “increases [Buck’s] future dangerousness”—a necessary element for a death sentence under that state’s law.

Cases such as these—not to mention the recent execution of Troy Davis, which spurred worldwide protests—receive focused attention both inside and outside the Court. The Court’s rules single out capital cases for special treatment, directing that the notation “CAPITAL CASE” appear at the beginning of any such request for review and mandating that the government, which often waives its right to reply, file a response. The clerk’s office has a special staff attorney charged with overseeing the voluminous, often last-minute filings in death penalty cases. The justices and their law clerks often scrutinize the filings with great care. The bar has also responded: death row inmates typically receive superb legal assistance before the Supreme Court. Former Bush Administration Solicitor General Gregory Garre is now representing Maples. Current Solicitor General Donald Verrilli previously represented several death row inmates pro bono before the Court.

But the concentration on capital cases comes at a cost. Ineffective trial lawyers, inconclusive evidence, inconsistent testimony, and impenetrable procedural thickets are hardly unique to capital cases. Nonetheless, the Court is far less likely to pay attention to these claims when the consequences to the defendant seem less harsh. Criminal law and procedure scholars such as Robert Weisberg of Stanford and Douglas Berman of Ohio State have described how the Court’s concern with death leads it to shortchange the constitutional claims of defendants facing lesser punishments. Berman has calculated that about one in ten thousand state felony sentences is a death sentence, yet the Court devotes more resources to reviewing death sentences than to reviewing claims in all other criminal cases combined. And while the Court has repeatedly considered whether a death sentence is proportionate to a particular class of crimes—for example, barring death sentences for non-homicide offenses or for juvenile or mentally retarded defendants—it has set virtually no limits on the severity of prison sentences. In the 40 years that the Court has been actively policing capital punishment, prison sentences have lengthened and the U.S. prison population has skyrocketed. With execution at the top end of the scale of punishment, a life sentence begins to look something like leniency, and other sentences are inflated in turn.

Capital cases also consume thousands of hours of legal services from some of the finest legal minds in America. The time those lawyers spend challenging death sentences of inmates whose guilt is not seriously in doubt could be spent preventing and remedying wrongful convictions, ensuring that all defendants receive prompt appointment of competent counsel, and attacking draconian prison conditions, not to mention providing civil justice to poor and disenfranchised people. But as long as the death penalty is with us, superb and committed lawyers at organizations such as the Southern Center for Human Rights, the Equal Justice Initiative, and the NAACP Legal Defense and Educational Fund will find themselves defending the lives of a few while the lives of many others continue to be ruined by pervasive flaws in our criminal justice system.