The Synergistic Evolution of Liberty and Equality in the Marriage Cases Brought by Same-Sex Couples in State Courts

I. INTRODUCTIONLegal scholars have expressed varying views about the role of liberty and equality in gay rights litigation. For example, in 1988, Professor Cass Sunstein took the position that the Due Process Clause is "backwardlooking," protecting "traditional practices against short-run departures."1 By contrast, he said that the Equal Protection Clause "looks forward, serving to invalidate practices that were widespread at the time of its ratification."2 Therefore, he encouraged gay rights litigators to lead with equality. In 2000, Professor William Eskridge challenged Sunstein's thesis. He examined the text and the history of the two clauses and concluded that both clauses are simultaneously present-looking, forward-looking, and backward-looking.3 Consequently, he took the position that the two clauses ought to be distinguished on the basis of their function.4 In the context of gay rights litigation, he suggested that plaintiffs' lawyers should rely first on the Due Process Clause (particularly in its more procedural aspects) for making disruptive challenges to statutes at the "retail level."5 Only later should they invoke "evolutive equal protection" for making broad facial challenges to statutes at the "wholesale level."6 More recently, Professor Kenji Yoshino encouraged gay rights litigators to lead with liberty on the theory that the recognition of liberty for all will serve to advance both liberty and equality.7 Finally, a fourth legal scholar, Professor Pamela Karlan, has suggested that "sometimes looking at an issue stereoscopically ? through the lenses of both the due process clause and the equal protection clause ? can have synergistic effects, producing results that neither clause might reach by itself."8 In other words, Professor Karlan's theory would suggest that sometimes gay rights litigators ought to lead with both liberty and equality simultaneously.This Article will examine selected marriage cases brought by same-sex couples in state courts in order to understand the role played by liberty and equality in this one segment of gay rights litigation. At first, neither liberty nor equality could dent the definition of marriage as an institution designed exclusively for opposite-sex couples.9 But gradually, over time, the interplay between the claims of liberty and equality began to alter the state courts' understanding of the institution of marriage. 10 It is the thesis of this Article (written with the benefit of 20/20 hindsight) that, by focusing on the two constitutional issues simultaneously, gay rights litigators in the state court marriage cases have sparked a synergistic evolution of both liberty and equality under state constitutional law.This evolutionary process has not been linear. Instead, the courts have typically taken two steps forward'1 and one step back.12 At times, the liberty claim and the equality claim have been in tension with one another.13 At other times, the two claims have complemented each other.14 Yet, at all times, the interplay between the two claims has challenged the judiciary to rethink the fundamental question of whether marriage is an exclusive institution for opposite-sex couples only.This Article will trace the synergistic evolution of liberty and equality in the state court marriage cases brought by same-sex couples. Its primary purpose is to demonstrate the effectiveness of advancing the two claims simultaneously when state constitutions are at issue. At the same time, gay rights litigators in federal court marriage equality cases15 may be interested in this Article as well because the assertion of the two claims simultaneously in the federal forum might spark a second, synergistic evolution of liberty and equality under the Federal Constitution.Finally, a subsidiary purpose of this Article is to parse and compare the holdings in the key state court marriage equality cases in order to identify each step in the process by which the courts gradually moved toward the extension of marriage to same-sex couples. …