On June 29, 1972, the U.S. Supreme Court effectively struck down the death penalty in Furman v. Georgia. 43 years later to the day, in Glossip v. Gross, the justices saved it from one existential threat—but doomed it to another. Had the Court ruled in favor of three death-row inmates in Glossip, which challenged Oklahoma’s lethal-injection protocol, it would have been a historic shift: Never before has the Supreme Court struck down a state’s chosen method of execution as unconstitutional.