Six times in Dobbs—on pages 32, 37, 38, 49, 66, and 71—the Court swears that the “potential life” principle, because it applies uniquely to abortion, will protect these other cases from being overturned. But not once does the Court cite a constitutional basis for that principle. In fact, the Court notes on page 38 that “nothing in the Constitution . . . authorizes the Court to adopt” a “particular theory about when the rights of personhood begin.”

In lieu of constitutional text, the Court quotes Roe and Casey, noting that they called abortion a “unique act” that is “inherently different from marital intimacy” because it terminates “potential life.” But where did Roe and Casey get those phrases? The justices who wrote Roe and Casey derived these concepts the same way they derived the right to abortion: by cobbling together a hodgepodge of historical analysis, intuitions, and flowery language. The state has an “important and legitimate interest in protecting the potentiality of human life,” said Roe, citing nothing in particular. “It is reasonable and appropriate for a State to decide that at some point” its interest in “potential human life . . . becomes significantly involved,” Roe added, again without visible support…

The constitutional groundlessness of the state’s asserted interest in “potential life” doesn’t mean that this interest isn’t important or that states can’t pass laws to protect the unborn. It just means that the Supreme Court can’t invoke this interest as a reason to insulate Griswold, Lawrence, or Obergefell from the logic of Dobbs. If the justices sincerely intend to purge past rulings that asserted rights not found in the Constitution, they can’t limit the purge based on a principle that’s also not found in the Constitution. They certainly can’t limit the purge based on a principle invented in Roe, the very case they’re purging.