An interesting theory implicit in Alito's Casey dissent

I've been reading Judge Alito's 3rd Circuit dissent in Planned Parenthood v. Casey. It's not as scary as some are assuming (or wanting others to assume). (NPR is giving out a short and greatly oversimplified version of what he wrote.) For one thing, the spousal notification statute in question let a woman avoid telling her husband about her abortion plans if she believed the husband was not the father, or if she had reason to believe that telling the husband would lead to anyone inflicting bodily injury on her. (Ditto if the pregnancy is the result of spousal rape, or if the husband can't be found.) That leaves women who think the fetus is the husband's, as the result of consensual intercourse, and who aren't afraid that the husband will respond with violence. It does not seem inappropriate that the father should be in the loop under those circumstances. Also, the spousal notification provision was essentially unenforceable -- a woman's statement that she'd told her husband did not have to be made under oath, or otherwise under penalty of perjury. Moreover, the plaintiffs' statistical evidence seems to have been on the thin side.

What's most interesting about the dissent from a technical point of view, and the aspect that I find possibly questionable, is how Alito handles the question of which level of scrutiny applies. Alito says that the outcome depends on whether one applies strict scrutiny or rational basis analysis, and that under Webster and Hodgson v. Minnesota, strict scrutiny only applies if the statute imposes an "undue burden" on the right to an abortion. I haven't reread all of Webster or Hodgson, so for now I'm assuming he's characterizing them correctly. Alito then goes on and quotes a number of Justice O'Connor's opinions, often dissenting opinions, in order to define "undue burden". He concludes that, per these opinions, an "undue burden" most be either an absolute prohibition, a severe limitation, or a substantial limitation of access. In his view, given the evidence presented, the plaintiffs didn't make the case that the spousal notification provision met the "undue burden" test as thus defined.

But does one really interpret key language in a U.S. Supreme Court decision by looking to how its author -- rather than the Court as a whole -- interpreted that language in other opinions, including dissenting opinions? And is the answer to that question affected by the fact that O'Connor's "undue burden" opinion in Webster was a one-Justice concurring opinion?

Of course, there may not have been a lot in the way of post-Webster discussion of "undue burden" by the Court as a whole, when Alito was writing....