The Supreme Court decided today that raping a child should not be punished with the death penalty.

Justice Kennedy said the decision reflects a “maturing society,” which apparently means “more forgiving of child rape.”

The reasoning appears to boil down to: if the child isn’t killed, the rapist shouldn’t be killed either. “Maturity?” This is grade-school level moral equivalence. Retch.

WASHINGTON — The Supreme Court ruled, 5 to 4, on Wednesday that sentencing someone to death for raping a child is unconstitutional, assuming that the victim is not killed.

“The death penalty is not a proportional punishment for the rape of a child,” Justice Anthony M. Kennedy wrote for the court. He was joined by Justices John Paul Stevens, David H. Souter, Ruth Bader Ginsburg and Stephen G. Breyer.

The court overturned a ruling by the Louisiana Supreme Court, which had held that child rape is unique in the harm it inflicts not just upon the victim but on society and that, short of first-degree murder, no crime is more deserving of the death penalty.

Justice Kennedy, while in no way minimizing the heinous nature of child rape, wrote that executing someone for that crime, assuming that the victim was not killed, violates the Eighth Amendment’s ban on cruel and unusual punishment, which draws it meaning from “the evolving standards of decency that mark the progress of a maturing society.”

“When the law punishes by death, it risks its own sudden descent into brutality, transgressing the constitutional commitment to decency and restraint,” Justice Kennedy wrote.