Of course, that Roberts could not see his way to joining the majority in Windsor makes it difficult to understand how he might conclude that state laws prohibiting same-sex couples from marrying are unconstitutional. But it’s not impossible. He might, for example, look to the Supreme Court’s 1967 decision in Loving v. Virginia, which held that state laws banning interracial marriage were unconstitutional. In Loving, the Court described marriage as “one of the ‘basic civil rights of man,’” and noted that “[t]he freedom to marry has long been recognized as one of the vital personal rights essential to the orderly pursuit of happiness by free men.” From these premises, it followed that “[t]o deny this fundamental freedom” on racial grounds violated both the Equal Protection and Due Process Clauses of the Fourteenth Amendment. As numerous lower courts have recognized, same-sex marriage bans are simply the modern analogue of interracial marriage bans, and they violate the Constitution for the same reason. Seventh Circuit Judge Richard Posner, for example, wrote in an opinion striking down same-sex marriage bans in Wisconsin and Indiana that the argument that tradition supported the bans “runs head on into Loving.” The Chief Justice could well conclude the same thing in the cases the Court has just agreed to hear. 

After all, Roberts has seen what a watershed decision Windsor has been, and he must surely recognize that if the Windsor majority takes the final step to recognize full marriage equality (as it should), that decision will be even more historic and undoubtedly one of the greatest legacies of the Roberts Court. Will Chief Justice Roberts be content to have such a momentous ruling be issued over his dissent, or will John Roberts want to be part of one of the greatest legacies of the Roberts Court?