This is not to deny that some of those released will commit violent crimes. People released from prison after serving their time often commit violent crimes. It's called recidivism.

Nor is this to deny that the dissenters in the prison release case, Brown v. Plata, made some strong points, especially as to the flaws in the lower court decision - by three of the most liberal activist judges in the country - that the majority nominally affirmed.

This case presented the justices with a tragic choice. Understandably, the five-justice majority did not want say, "Turn 37,000 criminals loose and let's hope they don't kill, rape, and rob too many people." And the four conservative dissenters - or, at least, Justice Samuel Alito and Chief Justice John Roberts -- did not want to say, "Let the cruel and unusual punishment continue forever."

(Justices Scalia and Clarence Thomas did not say that either. But they ruled out any and all broad court-ordered prison reforms, no matter how barbaric the treatment of thousands of prisoners nor how clear it be that the cruelty will continue without such court-ordered reforms.)

But after more than 15 years of litigation over disastrously deficient mental-health and other medical care in California's overcrowded prisons, the choice looks almost that stark.

And that helps explain why there may be less than meets the eye both to the decision and to the apparent gulf between the majority and the thoughtful Alito-Roberts dissent.

Indeed, the give-California-five-years admonition and other hedges in Justice Anthony Kennedy's opinion for himself and the four more liberal justices look like backhanded concessions to the strength of Alito's critique of the three-judge lower court.

Kennedy's hedges also go some distance toward satisfying the concerns that underlie the Alito-Roberts dissent -- although not, by a long shot, the far angrier Scalia-Thomas.

Scalia, who took the unusual step of reading his dissent from the bench, trashed the majority's decision as "radical," "absurd," "outrageous" and a "judicial travesty," all in his first three paragraphs.

But let's get back to the semi-convergence between the logic of the far more measured Alito-Roberts dissent and that of Kennedy's majority opinion.

Alito argues persuasively that the three-judge lower court "relied heavily on outdated information and findings and refused to permit California to introduce new evidence" showing recent improvements in prison conditions and medical care.

Kennedy sort-of-responds by excusing the lower court's odd approach while making clear that it should modify the decree either if evidence that the lower court has not yet considered shows that prison medical care has already improved, as demonstrated to some extent by Alito, or if new evidence shows improvement over the next five years.