The record of systemic disparities in U.S. capital cases is long and well documented. Compounding the biases that pervade the entire criminal-justice system, including in jury selection, states are more likely to seek and secure a death sentence in cases involving white victims, especially if the defendant is black. But while studies have consistently shown that these disparities exist in capital-punishment systems around the country, the success of discrimination-based challenges to the death penalty has been piecemeal. The Supreme Court has heard a number of arguments about racial discrimination in capital cases over the past three decades, and has found in favor of several of the defendants, but the scope has almost always been limited to individual cases of discrimination.
After empirical evidence of systemic bias was first published decades ago, it was almost used to strike a major blow to the criminal-justice system, in the 1987 Supreme Court case McCleskey v. Kemp. Lawyers for Warren McCleskey, a black man sentenced to death in Georgia for killing a white police officer during an armed robbery, argued on appeal that capital punishment in the state was racially discriminatory and violated McCleskey’s Fourteenth Amendment right to equal protection. They based their allegations of unconstitutional discrimination on a landmark statistical study showing significant racial disparities in the administration of the death penalty in Georgia. The case brought the Court within one vote of potentially striking down capital punishment in the state—but instead affirmed a standard that civil-rights advocates have been fighting ever since.
In a contentious 5–4 decision, the Court determined that general disparities in a state’s capital-punishment system were not enough to demonstrate unconstitutional discrimination in an individual defendant’s case. In a memo to his fellow justices, Antonin Scalia wrote that racial biases have a “real” and “ineradicable” influence on “jury decisions and (hence) prosecutorial decisions”—and yet he didn’t believe that bias was enough to invalidate those decisions.
Justice Lewis Powell, writing on behalf of the majority, even noted that the arguments in the case “basically challenge the validity of capital punishment in our multiracial society.” But, citing a standard previously established in civil law, he too concluded that the Court couldn’t find that McCleskey’s rights had been violated solely based on the discriminatory impact found in the study; McCleskey’s lawyers would have also needed to prove that the state had intended to discriminate against him.