A generation from now, I suspect, archived notes and memos will reveal a behind-the-scenes drama of hesitations, compromises, and last-minute appeals that shaped Friday’s historic decision affirming that “same-sex couples may exercise the fundamental right to marry.” Nothing this momentous happens smoothly.

But from the outside, neither the Court’s 5-4 decision in Obergefell v. Hodges and the allied cases, nor the opinion announcing it, nor the lineup of justices on each side, was surprising.

After Justice Anthony Kennedy finished reading a summary of his opinion, the arc that led to June 26, 2015, seemed clear. In 1986, in Bowers v. Hardwick, the Court had held that gay and lesbian sex could be made a crime, and termed the contrary argument “facetious,” a joke.* 10 years later, in Romer v. Evans, a new Court had begun to turn: Whether Bowers was right or wrong, no state could make gays and lesbians “stranger[s] to its laws.”* Seven years later, in Lawrence v. Texas, the Court overturned Bowers and affirmed that gay people could form lasting relationships and “still retain their dignity as free persons.”* Two years ago, in United States v. Windsor, it held that the federal government could not refuse to recognize same-sex marriages legal under state law because the Defense of Marriage Act laid “a stigma upon all who enter into same-sex marriages made lawful by the unquestioned authority of the States.”

At some point, Obergefell had become inevitable. And curiously enough, that seeming inevitability sparked the most important disagreement between Kennedy (who was joined by Justices Ruth Bader Ginsburg, Stephen Breyer, Sonia Sotomayor, and Elena Kagan) and the dissenters. Both Chief Justice John Roberts, in his civilly worded principal dissent, and Justice Antonin Scalia, in his venomous personal assault on Kennedy, wrote against a seeming assumption that same-sex marriage advocates were winning the fight outside the courtroom, and that the court was thus intruding in a struggle that did not concern it.

Certainly those who scorn Kennedy’s poetic style will dislike Friday’s opinion. Beginning with Confucius and Cicero, he paused briefly at Alexis de Tocqueville to make his case that “the right to personal choice regarding marriage is inherent in the concept of individual autonomy.” That is because “marriage responds to the universal fear that a lonely person might call out only to find no one there.” Denying it to same-sex couples “has the effect of teaching that gays and lesbians are unequal in important respects.”

But even those who find such flights annoying should read the opinion carefully, because it methodically tackles the issues the nation and the courts have debated over more than a decade—the history of marriage, its relationship to reproduction, and the need for “caution” in proclaiming such an important change. At oral argument, Kennedy had challenged gay-rights lawyer Mary Bonauto with the claim that opposite-sex marriage had been a firm social principle over “millennia and time.” In the opinion, however, Kennedy notes an elementary fact of history: No human institution is, in the long run, free from slow but radical change. From the arranged marriages once common everywhere (and still practiced here and abroad) to the patriarchal institution of the common law, which literally merged a married woman into her husband’s person, to today’s nominally egalitarian unions, “the institution has evolved in substantial ways over time, superseding rules related to parental consent, gender, and race once thought by many to be essential.”

At the same time, history revealed first the existence, and then the worthiness, of LGBT people—whose behavior was “treated as an illness” for most of the last century, and who emerged slowly as legislatures and courts began to recognize their fundamental rights. “The nature of injustice is that we may not always see it in our own times,” Kennedy wrote. “The limitation of marriage to opposite-sex couples may long have seemed natural and just, but its inconsistency with the central meaning of the fundamental right to marry is now manifest.” The Fourteenth Amendment’s twin promises of due process “liberty” and equal protection require us to re-examine exclusions, however venerable their pedigree: “Rights come not from ancient sources alone. They rise, too, from a better informed understanding of how constitutional imperatives define a liberty that remains urgent in our own era.”

In its final section, Kennedy’s opinion engaged the argument that courts should allow the political process to resolve this issue. The right to marry is an individual right, not a broad social policy:

The dynamic of our constitutional system is that individuals need not await legislative action before asserting a fundamental right. The Nation’s courts are open to injured individuals who come to them to vindicate their own direct, personal stake in our basic charter. An individual can invoke a right to constitutional protection when he or she is harmed, even if the broader public disagrees and even if the legislature refuses to act.

The petitioners in this case are people, whose lives are fleeting, he noted. If there is a right to marry, then barring them from marriage for even one of their days on earth is a deprivation of that right, and being told to be patient is not a fit judicial response. In addition, he argued, denying the claim to same-sex marriage is itself an intervention in the democratic process, because it would “would teach the Nation that these [same-sex marriage bans] are in accord with our society's most basic compact.”

This political-process argument forms the major disagreement between the majority and the four dissenters. Each dissenting justice wrote a separate opinion. Justice John Roberts insisted that the majority was not including same-sex couples in marriage, but rather, changing its definition. Justice Clarence Thomas dissented, in part, because “liberty is only freedom from governmental action, not an entitlement to governmental benefits.” Alito asserted that the decision will reinforce a view of marriage that “focuses almost entirely on the happiness of persons who choose to marry,” in contrast to the focus of “traditional marriage” on biological procreation.

But each dissenter, in the end, centered his argument on the perceived illegitimacy of deciding this issue in court rather than at the polls. Roberts, whose principal dissent gained the support of Scalia and Thomas, wrote that “supporters of same-sex marriage have achieved considerable success persuading their fellow citizens—through the democratic process—to adopt their view. That ends today. Five lawyers have closed the debate and enacted their own vision of marriage as a matter of constitutional law. Stealing this issue from the people will for many cast a cloud over same-sex marriage, making a dramatic social change that much more difficult to accept.”

In his separate dissent, Scalia wrote that he really didn’t care one way or the other about same-sex marriage, only about who should have decided it. It shouldn’t be decided by a judge, he argued, and especially not by Anthony Kennedy. Kennedy’s opinion, he said, is “lacking even a thin veneer of law,” filled with “mummeries and straining-to-be-memorable passages,” written “in a style as pretentious as its content is egotistic.” An acid footnote said that “If I ever joined an opinion” filled with Kennedy’s rhetoric, “I would hide my head in a bag.” Kennedy’s logic took the Court from “disciplined legal reasoning ... to the mystical aphorisms of the fortune cookie.”

The democratic process argument—whether coolly phrased by Roberts or angrily brandished by Scalia, Thomas, and Alito—has a certain appeal. The political victories of the past decade—recognition of gays in the military, the abandonment by the executive branch of the Defense of Marriage Act, victories in marriage referenda—were exhilarating. They have created a sense of inevitability for gay rights in general and marriage equality in particular. Why, then, should courts jump ahead of the parade?

But that argument is wrong. Over the past four decades, the forward or retrograde movement of gay rights has been shaped at every step by the courts. Bowers legitimated scorn for LGBT people and helped inspire the referendum on gay marriage that took place in Colorado in 1992, which the Court struck down in Romer. After that decision, those referenda ceased.* Lawrence took sodomy laws off the table; thus it became possible for gay people and couples to emerge from the shadows. As they stood in the sunshine, they became, for many straights, neighbors rather than terrifying phantoms. A court decision in Massachusetts put same-sex marriage on the agenda. Courts have been as essential to that progress as air is to life.

For the Court to have traveled this far and then paused in the name of “self-government” would have been so perverse as to be all but unimaginable. Instead, the Court in 2015 kept the promise it had begun to make, almost without knowing it, in 1996.


* This article originally misstated the dates of several Supreme Court rulings: Bowers v. Hardwick was decided in 1986, not in 1983. Romer v. Evans was decided in 1996, not in 1999. Lawrence v. Texas was decided in 2003, not in 2006. Additionally, it misstated the details of a referendum vote in Colorado, which established language in the state’s constitution preventing gays and lesbians from receiving protected status under the law. That referendum took place in 1992, not 2008, and it took place in Colorado, not California . We regret the errors.