WITH gay marriage litigation moving forward at warp speed — federal judges have struck down five state bans on same-sex marriage since December — we may soon witness one of the worst shouting matches in Supreme Court history. Passions were already running high last June, when a divided court struck down federal, but not state, laws defining marriage exclusively as a relationship between a man and a woman. Justice Antonin Scalia denounced the majority opinion, which cited the demeaning and humiliating effects of the Defense of Marriage Act, as “legalistic argle-bargle” lacking any basis in our constitutional tradition. Writing for the five justices in the majority, Justice Anthony M. Kennedy countered that the assault on human dignity should be decisive in condemning the statute as unconstitutional.

In making this “dignitarian” move, Justice Kennedy relied principally on his two earlier pathbreaking opinions supporting gay rights, in 1996 and 2003. He did not link his guiding philosophy to the broader principles hammered out during the civil rights revolution of the 1960s. Yet that constitutional legacy would strongly support any future Supreme Court decision extending Justice Kennedy’s reasoning to state statutes discriminating against gay marriage. Indeed, the court should reinforce its dignitarian jurisprudence by stressing its roots in the civil rights revolution — and thereby demonstrate that it is Justice Scalia, not Justice Kennedy, who is blinding himself to the main line of constitutional development.