Brennan Linsley/Associated Press Justice Antonin Scalia predicted some liberal implications down the road. He's been right on that before.

Justice Antonin Scalia didn't make it to the Supreme Court this week, but he did leave a snippy note for Justice Anthony Kennedy in a major juvenile justice case decided Monday.

The decision in Montgomery v. Louisiana made retroactive a 2012 ruling that said it's unconstitutional to automatically sentence children to life in prison without the possibility of parole. Monday's decision split the court 6-3, with Kennedy writing for the majority and Scalia for the dissenters.

What the decision means in practice is that potentially thousands of lifers -- adults who were sentenced to die in prison for crimes they committed as kids -- may be granted hearings at which they can argue they should receive mercy.

Scalia wasn't happy with the ruling, as he hasn't been in other cases where the court has shown a little leniency to certain classes of offenders. To explain his beef, he gave Kennedy a history lesson -- along with his usual sarcasm and snide commentary.

First, he went back to the 2012 decision, Miller v. Alabama, which prohibits sentences of life without the possibility of parole for "all but the rarest of children, those whose crimes reflect irreparable corruption."

In that ruling, Scalia said, the Supreme Court had bent over backward to restrict the states as little as possible.

He quoted directly from Miller: "Our decision does not categorically bar a penalty for a class of offenders or type of crime. Instead, it mandates only that a sentencer follow a certain process -- considering an offender's youth and attendant characteristics -- before imposing a particular penalty."

In other words, Scalia said, all the 2012 decision did was tell states that they must guarantee youthful defendants a procedure at the time of trial in which they might be granted a chance for future release. Nothing more, nothing less.

Denis Poroy/Associated Press Justice Anthony Kennedy was the target of Scalia's legal ire this time around.

But Scalia said that Kennedy's opinion in the new case dances around this clear language in an effort to make Miller apply retroactively. In so doing, Scalia charged, the court goes beyond the original decision, "rewriting" it in such a way that it now imposes a heavy burden on states.

"How wonderful," he mused, before contending that courts now face the "knotty legal question" of how to go back in time with every single once-youthful offender who's now serving life, to consider re-sentencing them to a less punitive term -- all while weighing whether the inmate was incorrigible at the time of the crime. (Henry Montgomery, the man at the center of the case, was sentenced nearly 50 years ago.)

"What silliness," Scalia said, deriding the new regime as "a practical impossibility."

Of course, Kennedy's majority opinion offered a way to deal with the impracticalities -- by granting parole hearings in which the board may focus on who the inmates are now, not who they were as teenagers. That kind of micromanagement really set off Scalia, for here he saw an agenda at work.

"This whole exercise, this whole distortion of Miller, is just a devious way of eliminating life without parole for juvenile offenders," he declared.

Then came the coup de grâce.

Scalia pointed Kennedy to the latter's own majority opinion in the landmark Roper v. Simmons, which held in 2005 that sentencing juveniles to the death penalty is unconstitutional. In that case, Kennedy wrote that life without parole remained a severe enough alternative for those youths the state could no longer kill.

"How could the majority -- in an opinion written by the very author of Roper -- now say that punishment is also unconstitutional?" Scalia wondered, essentially accusing Kennedy of flip-flopping on life without parole.

"And then, in Godfather fashion," Scalia continued, "the majority makes state legislatures an offer they can't refuse: Avoid all the utterly impossible nonsense we have prescribed by simply permitting juvenile homicide offenders to be considered for parole."

Not that Scalia never flip-flops himself. But he has a point here: Sending all those lifers to the parole board sounds much easier than trying to conduct proper re-sentencing hearings in so many old cases.

Plus, it is anyone's guess what lower courts will do with the Supreme Court's new "permanent incorrigibility" requirement for sentencing youth to die in prison. It sounds like a high standard, one that will likely lead to heaps of litigation over which youthful offenders should or shouldn't face life without parole. (Which, it should be noted, remains constitutional.)

If discouraging life without parole was the majority's intent all along, then Scalia's closing words could well reverberate: "Mission accomplished."