The court is wrong.
As Lyle observes, the court has been progressively narrowing the conditions under which the death penalty can be used. By itself, this is a frustrating fact as the court appears to be referencing reasons with less basis in law and more basis in their feelings. Lyle observes:
…the longer a Justice stays on the Court and watches capital cases come and go, the greater the prospect that capital punishment will lose another vote…
But more disturbing is the fact that the court has taken the most offensive, the most evil crime next to murder, and essentially issued a free pass. If a little girl can be gruesomely raped by an adult and the death penalty is too “cruel and unusual”, then where is the hope of justice?
Just as important is the fact that the court continues to dig itself further and further into countering the legitimate efforts of state legislatures and the US Congress. Although there are clearly cases where this is a necessary role for the court, they have come close to making this a full-time job.
Here’s the crux of court’s decision  with respect to the 8th amendment (to the US Constitution):
Held: The Eighth Amendment bars Louisiana from imposing the death penalty for the rape of a child where the crime did not result, and was not intended to result, in the victimâ€™s death. Pp. 8â€“36.
1. The Amendmentâ€™s Cruel and Unusual Punishment Clause â€œdraw[s] its meaning from the evolving standards of decency that mark the progress of a maturing society.â€ Trop v. Dulles, 356 U. S. 86, 101. The standard for extreme cruelty â€œitself remains the same, but its applicability must change as the basic mores of society change.â€ Furman v. Georgia, 408 U. S. 238, 382. Under the precept of justice that punishment is to be graduated and proportioned to the crime, informed by evolving standards, capital punishment must â€œbe limited to those offenders who commit â€˜a narrow category of the most serious crimesâ€™ and whose extreme culpability makes them â€˜the most deserving of execution.â€™ â€
There’s something deeply wrong when the court becomes so self-deluded in its own divine power that it believes it knows what society, that is the people, want(s) more than the actual elected representatives of the people. But there it is: the court believes it actually knows better. This is why it is so important that we have constructionist judges on the court instead of this generation of activist jurists.
Obama, for his part, opposes the court’s decision. This is also unbelievable. Eliminating the death penalty is a traditional liberal position, so this was a surprise. I’m not sure what’s behind this aside from his attempt to “reinvent himself”.