You may have heard that Justice Antonin Scalia referred to the majority opinion striking down the Defense of Marriage Act as "legalistic argle-bargle."

Intemperate as the dissent was, derision for Justice Anthony Kennedy's jurisprudence of dignity and personhood was nothing new for Scalia, who has been castigating what he once called Kennedy's "sweet mystery of life" rhetoric for a decade.

What's new about Scalia's numerous dissents issued over the U.S. Supreme Court's remarkable June is how much he's been criticizing the younger conservatives who were supposed to be the heirs to his mantle: Chief Justice John Roberts, he of the Obamacare cave, and Justice Samuel Alito, once so close to Scalia that court-watching wags called him Scalito.

It started with Scalia's libertarian dissent in the DNA-collection case Maryland vs. King. The majority upheld standard DNA collection on arrest, nominally for the purpose of keeping track of arrestees but actually (as Scalia convincingly argued) to help solve crimes. Scalia's central objection was that such collection was a search under the Fourth Amendment, and therefore required a warrant. Yet he undermined his authority by writing a dissent dripping with contempt for the majority opinion, which was written by Roberts and joined by all the conservative justices and Stephen Breyer.

"The court's assertion" of DNA collection's purpose, Scalia wrote, "taxes the credulity of the credulous." The court's claim that the state was collecting DNA for identification purposes was, he wrote, false and dangerous: "I hope that the Maryland officials who read the Court's opinion do not take it seriously. Acting on the Court's misperception of Maryland law could lead to jail time." All this in a dissent joined only by liberal justices Ruth Bader Ginsburg, Elena Kagan and Sonia Sotomayor.

Scalia went after another Roberts opinion, also joined by Alito, in Agency for International Development vs. Alliance for Open Society International Inc., a case about what conditions the government can put on funding recipients. This time, Roberts got off easy: Scalia restricted himself to observing that he was "at a loss to explain what this central pillar of the Court's opinion ... has to do with the First Amendment."

The elder conservative's distaste for Alito's rejection of traditional conservatism came out in Adoptive Couple vs. Baby Girl, in which Alito wrote for the majority that denied the biological father's rights under the Indian Child Welfare Act. Once again, Scalia joined the liberal (and female) troika of Ginsburg, Kagan and Sotomayor.

Scalia embraced almost all of Sotomayor's statutory reasoning then added: "While I am at it, I will add one thought." The thought was a doozy, accusing Alito of denying the common-law tradition of respect for biological parents. "This father wants to raise his daughter," Scalia said, "and the statute amply protects his right to do so. There is no reason in law or policy to dilute that protection."

For one conservative Catholic to charge another with diluting the protection of parenthood is no small affair — but Scalia meant it.

All these jibes at Roberts and Alito are something new for Scalia — the sitting justice who perhaps has the best chance to go down as truly great, if deeply flawed. Sideswipes at other justices have always been part of the Scalia repertoire; one criticism of a Sandra Day O'Connor opinion as "simply irrational" was reputed to have lost him her respect. But attacking O'Connor and Kennedy was attacking "wets" — fake conservatives who didn't keep the faith.

In contrast, Roberts and (especially) Alito were reared at the altar of Scalian values. Their failure to live up to his constitutional ideals must be especially galling. To wait for reinforcements, as Scalia did for so many years on the court, then find they are inadequate, is an insult of a special kind.

Scalia is a unique figure on the bench, saying things other justices don't even think. As a law professor, I couldn't do without him, and I love hearing him articulate the most extreme positions with implacable logic and a total lack of filter.

When, in the recent gene-patent case Association for Molecular Pathology vs. Myriad Genetics Inc., he insisted unashamedly that he had no idea whether the science was even true, I wanted to stand up and cheer.

Scalia's longtime antagonists say the past month proved he's over the hill and out of touch. They miss the point. This is the twilight of the gods for the 77-year-old red-wine-and pizza-loving legend. To see his judicial sons abandon him is painful.

To see him throw it in their faces is a joy.

Noah Feldman is a law professor at Harvard University.