At Cato@Liberty, my esteemed co-author Ilya Shapiro has a post on McDonald titled  Properly Extending the Right to Keep and Bear Arms to the States

Ilya provides a breakdown of the five different positions in McDonald the Justices can take. He is confident there are 5 votes for Incorporation of the Second Amendment, but Justice Thomas may be the only Justice willing to use the Privileges or Immunities Clause.

But I’m curious. What happens if there is a 4-1-4 split as follows:

• Chief Justice Roberts, Justice Scalia, Justice Kennedy, and Justice Alito vote to incorporate the Second Amendment through the due process clause and strike down the Chicago law
• Justice Thomas rejects incorporation through the Due Process Clause, and chooses to extend the right to keep and bear arms (cf. 2nd Amendment) to the states through the Privileges or Immunities Clause, and strikes down the Chicago Law
• Justice Stevens, Justice Ginsburg, Justice Breyer, and Justice Sotomayor, uphold the validity of substantive due process incorporation but find that the Second Amendment should not be incorporated, and finds the Chicago law constitutional

Under the “Marks Rule” Marks v. United States, 430 U.S. 188 (1977), what would the precedent be in such a situation?

As best as I can tell, there are five votes to extend the the right to keep and bear arms to the state. There are five votes to strike down the Chicago Law. But there will be no majority on how to extend the right.

I think, the gun ban falls and people living in the states have the individual right to keep and bear arms (but not the Second Amendment). And this would not foreclose the validity of Privileges or Immunities.

I am far from an expert on Marks, but this seems to be a highly possible outcome.

This may, in fact be a best case scenario. If the Court fragments 4-1-4, the Privileges or Immunities Clause can be reinvigorated with but a single vote.

For more thoughts on McDonald, check out.“Keeping Pandora’s Box Sealed: Privileges or Immunities, The Constitution in 2020, and Properly Extending the Right to Keep and Bear Arms,