Justice Anthony M. Kennedy may be the middleman in the gun-rights debate – It was the Supreme Court’s two hunting buddies — Elena Kagan and Antonin Scalia — who squared off last week when the divided court upheld criminal penalties for people who lie about their true intentions when they buy guns.  But those who follow the court’s jurisprudence on gun control were more interested in what the decision said about a third justice, Anthony M. Kennedy.