Today's unusual Supreme Court lineup

The first opinion issued this morning by the Supreme Court produced yet another unusual lineup of justices.

The case, Mathis v. United States, concerned when state-law criminal offenses satisfied the requirements of predicate offenses for sentence enhancements under the Armed Career Criminal Act. In this case, a majority of the court concluded that a conviction for burglary under Iowa law did not trigger the ACCA sentence enhancement because the elements for this offense under Iowa law are broader than those of generic burglary.

Here's where things get interesting: Justice Elena Kagan wrote the majority opinion, joined by Chief Justice John Roberts and Justices Anthony Kennedy, Clarence Thomas and Sonia Sotomayor. (Kennedy and Thomas also wrote concurrences.) Justice Stephen Breyer dissented, joined by Justice Ruth Bader Ginsburg, and Justice Samuel Alito dissented as well. This is neither a traditional right-left lineup, nor is it the sort of formalist-pragmatist lineup we often see in criminal procedure and sentencing cases.

This is hardly the first unusual lineup we've seen this term. I've blogged about some others here, here, here and here.