What was the impact of the Supreme Court case Gregg v. Georgia?

In Gregg v. Georgia, the Supreme Court ruled that the death penalty for murder did not violate the Eighth Amendment's protection against "cruel and unusual punishment". It clarified the Court's position in a case four years earlier, Furman v. Georgia, that had ruled that in some cases, the death penalty did in fact violate this amendment. In that case, the Court had ordered that states had to be sure that they were not being discriminatory in their sentencing (in many states, minorities convicted of serious crimes were disproportionately more likely to receive a death sentence). Most states had discontinued the use of the death penalty in the wake of Furman, and the Court's decision in Gregg led many of them to reinstate the death sentence. So the Court, through this ruling, gave continued (or restored) constitutional legitimacy to the death penalty in murder cases.