I've taken a first quick look at how the McDonald opinions deal with the Privileges and Immunities Clause. As has been widely reported, only Justice Thomas was ready to revive the PIC and use it to incorporate the 2nd Amendment, while Justice Alito's opinion (joined by three other Justices on this point) "decline[d] to disturb" the current minimalist interpretation. However, the Alito opinion did quote and paraphrase some pretty strong statements about the scholarly consensus opposing that interpretation.
Alito et al.'s refusal to reopen the debate on the PIC seems to be based on two factors:
--The many decades of "substantive due process" precedent offer a usable framework; and
--Neither the petitioners in McDonald nor the scholars who have pointed out the flaws in the minimalist interpretation have provided a coherent explanation of how far the PIC would reach.
Justice Thomas describes the substantive due process approach as "rest[ing] on such tenuous footing" that he cannot endorse it. I suspect he would have more company in this view if it were not for the undefined scope of the PIC. Should some future litigant (or amicus curiae) come forward with an intelligible and historically supported definition of what the PIC should cover, we might see some interest from Justice Alito and/or from one or more of the Justices who joined his opinion.
The problem is related to the problem of how to interpret -- and, some hope, resuscitate -- the 9th Amendment. If the PIC covers more than the first eight amendments to the Constitution, it arguably covers the same rights that are protected from federal infringement by the 9th Amendment.