As early as December 2009, I identified a possible 4-1-4 split in McDonald v. Chicago with Justice Thomas concurring in judgment. That is precisely what happened. David Cohen wrote a number of posts about what he dubbed the Paradox of McDonald v. Chicago, which I addressed here, here, and here. The final version of the article is available on the GW Law Review Arguendo. Here is the abstract:

On the last day of its 2010 Term, the Supreme Court issued the landmark decision of McDonald v. City ofChicago, holding that the Second Amendment is incorporated against state and local governments.  On its face, the 5–4 decision is simple enough, as a majority of the Court concluded that the 2008 decision inDistrict of Columbia v. Heller, which held that the Second Amendment protects an individual’s right to own a handgun, applied to state and local governments, such as the city of Chicago, just as it applied to the federal government and its territories, such as the District of Columbia.  However, this simple statement ofMcDonald’s holding masks a much more complicated reality—that its outcome, an instance of a rare phenomenon called a “voting paradox,” turned not on grand theories of constitutional law, history, or doctrine, but rather on the minutiae of Supreme Court vote counting.  In fact, only because the Court reaches a conclusion based on each Justice’s vote on the case’s outcome, as opposed to voting on the case’s individual issues, were the headlines following McDonald that gun rights prevailed and gun regulation lost, rather than the other way around.

This Essay explains why McDonald is an important example of a voting paradox.  The Essay first walks through the opinions in McDonald and then places McDonald in the context of relevant social choice theory that models voting paradoxes on multimember judicial bodies.  Having described how McDonald fits into this literature, the remainder of the Essay discusses three significant lessons that come from viewing McDonald as a paradox.  First, McDonald illustrates the importance of the Supreme Court’s voting rules, which decide cases based on outcome voting.  Second, McDonald is a lesson to litigators of the value of including additional arguments.  Finally, McDonald shows the considerable role of precedent-in-flux in creating voting paradoxes.