Will Saletan picks the wrong fight
In Hodgson the court considered a Minnesota law that included a provision (called "subdivision 2") requiring minors to notify both of their parents 48 hours before having an abortion. The law contained an additional provision ("subdivision 6") that would be effective only if a court ruled subdivision 2 to be unconstitutional. Subdivision 6 was identical to subdivision 2 but provided a judicial bypass exception to the parental notification requirement. The Supreme Court split in its Hodgson ruling: O'Connor joined the four liberal justices in striking down subdivision 2 -- two-parent notification without judicial bypass -- as unconstitutional. O'Connor joined the four conservative justices in upholding subdivision 6 -- two-parent notification with option of judicial bypass -- as constitional. (Notice that O'Connor managed to cast two swing votes in one case.)
Now it's important to keep that scenario straight because Saletan relied on the case's complexity to mislead his readers. The paragraph of Hodgson he cites, in his attempt to prove that the Supreme Court believed one woman to be enough adults to decide to have an abortion, is taken from Steven's opinion striking down subdivision 2 -- two-parent notification without judicial bypass. But in upholding the constitutionality of subdvision 6, O'Connor made it perfectly clear that she doesn't see a constitutional problem with the two-adult notification requirement; the judicial bypass is dispositive: "Subdivision 6 passes constitutional muster because the interference with the internal operation of the family required by subdivision 2 simply does not exist where the minor can avoid notifying one or both parents by use of the bypass procedure."
Because O'Connor held the two-parent (two-adult) notification requirement in subdivision 6 to be constitutional, and switched votes between subdivisions 2 and 6 solely due to the absence or presence of a judicial bypass option, Alito correctly ruled that Casey's inclusion of a judicial bypass option to the spousal notification requirement preserved its constitutionality according to O'Connor's undue-burden test.
And there's no way Alito could have known that O'Connor's oatmeal would be cold and pasty the following year.