I’m not going to pretend like Kennedy was clearly right. Scalia raised some strong arguments. But Kennedy had some strong arguments of his own. The case was a close call, and there were good arguments on both sides. Like so many other issues in constitutional law, there was no one right answer, but merely a range of plausible answers.
Obviously the conservatives went nuts. They turned into a band of lemmings that all agreeded with whatever the first one said. I swear that half of the people still haven't read the opinion. I know that many didn't read it before they spouted their views. They won't admit that but I know from reading their conclusory statements that either they did not read Kennedy or they know absolutely nothing about the law.
Why I disagree with Legal Fiction is a little more nuanced. It took me awhile to get to this point, but I would argue that the evolving standards test was the proported test in this case. If that had been followed it would not have been wrong. However, I don't think that Kennedy really used the evolving standards test to reach his holding. There is one other test that is acceptable as a matter of precendent. That is the proportionality test that is used in 8th Amendment jurisprudence. If you go back and carefully read the opinion you will see that Kennedy actually decided the case based on proportionality.
That is why I think Kennedy was clearly right.
Of course, the juvenile murderers will continue as they will...