The Supreme Court’s recent decision in United States v. Windsor is best understood from a Legal Process perspective. Windsor struck down Section 3 of the federal Defense of Marriage Act (“DOMA”), which defined marriage as exclusively between a man and a woman for purposes of federal law. Much early commentary, including Professor Neomi Rao’s essay in these pages, has found Justice Kennedy’s opinion for the Court to be “muddled” and unclear as to its actual rationale. But the trouble with Windsor is not that the opinion is muddled or vague; the rationale is actually quite evident on the face of Justice Kennedy’s opinion. The trouble is simply that it is not the rationale that many observers expected or wanted.