The fall of 1995 does not really seem all that long ago, does it? To me, it is as vivid as yesterday, yet also ancient as Babylon. I am walking with my father in Belfast, Ireland, and he is urging me to abandon my rash idea, which is to write in support of same-sex marriage. Why? I am puzzled: he has nothing against gay people, nor any disapproval of his gay son. The problem, he admonishes me, is that the idea of a man marrying a man, or a woman marrying a woman, is nuts. In fact, it is so far outside the realm of the possible that I will ruin my credibility as a journalist by supporting it. People will think I am nuts.

In 1995, his advice was not unreasonable. The idea of same-sex marriage seemed disgusting or risible to its opponents (who were practically everybody) and a pipe dream to its supporters. Some advocates imagined that their grandchildren’s generation might just possibly live to see it. In January of 1996, when I worked at The Economist magazine and we published a cover leader endorsing same-sex marriage, the mail which poured in was exceeded in volume and hostility only by the onslaught against the magazine’s call for the abolition of the monarchy.

For years, in the United States, marriage equality advocates faced what seemed to be an intractably opposed public. I would often say that opinion was remarkably stable, with roughly a third of the public (actually a bit less) supporting gay marriage, a third supporting legal partnerships instead of marriage, and a third opposed to all legal recognition of gay relationships. Court cases stalled, legislatures turned their backs. After Massachusetts’s supreme court ordered same-sex marriage in that state in 2003, our side lost in every single one of the 30 states where bans on marriage equality went before the voters: to my knowledge, the most unblemished losing streak in American political history.

And in 2013, as I write these words, a new national poll, by the Pew Research Center on the People and the Press, finds a strong majority of Americans, on both sides of the issue, saying that gay marriage is inevitable.

In 30 years of covering the American political scene, I have never seen a change as quick and dramatic as this one. Even (I should say, especially) those who have been in the thick of it from the beginning are scratching our heads, wondering why the tide turned so rapidly. I think part of the answer is that a number of things went right, from gay marriage advocates’ point of view, more or less simultaneously. And part of the answer has not much to do with marriage at all.


Incomplete but Inevitable

It is important to begin with a caveat: in the United States, the battle over same-sex marriage is not over. Rumours of victory are exaggerated. Gay marriage, in recent Pew findings (which are similar to what other polls find), enjoys majority support, but only just; the margin in mid-2013 was 51 per cent versus 42 per cent. Opposition is concentrated, and increasingly culturally isolated, among Protestants, especially white evangelicals, but their dissent remains fierce: evangelical whites are more than three-to-one against, a wall of opposition. Opponents, moreover, are a disproportionately influential component of the Republican Party’s electoral base, often willing to veto any political candidate who supports gay marriage. As a result, one of the country’s two major parties remains pinned in opposition.

Gay marriage’s losing streak in state initiatives ended decisively in 2012, when marriage equality won in all four states where it was on the ballot. Thanks to those victories — plus some recent legislative enactments and the US Supreme Court’s reinstatement of same-sex marriage in California — 13 states and the District of Columbia, representing 30 per cent of the population, have gay marriage. But support is spotty; according to an analysis of state opinion data by the Williams Institute (part of the law school at the University of California at Los Angeles), support is below 45 per cent in about half of the states, and below 40 per cent in most of the South. The states that have adopted same-sex marriage have been blue ones; the red states are much less receptive, and many have amended their constitutions to forbid same-sex marriage. Adoption in some of these states may be quite some time in coming, unless the Supreme Court steps in and imposes a national policy — something it declined to do in June of 2013, when it had the opportunity.

Why, then, the sudden aura of inevitability? Perhaps an overreaction to an uncharacteristic spate of victories for marriage equality? Perhaps, but probably not. Not one or two but a handful of important changes have taken place, more or less all at once. None of them is likely to be reversible, nor does any contrary trend appear likely to emerge.

Begin with the obvious: demographics. It is very important, but perhaps not as important as you think. Support for gay marriage is correlated with age; three in four Americans under 30 favour it. Gay marriage opponents are dying off and being replaced with proponents. More is going on than generational replacement, however. We know this because support has increased impressively among every generational cohort. Tellingly, support almost doubled over the past ten years, Pew finds, among “silent generation” members born between 1928 and 1945 — people in their late 60s and older. A lot of Americans, not excluding older Americas, have changed their minds.

One reason is what I think of as the Tocqueville effect. Alexis de Tocqueville, the Frenchman whose observations of America in the 1830s remain shrewdly relevant, famously remarked on Americans’ deference to majority opinion: “As long as the majority is still undecided, discussion is carried on; but as soon as its decision is irrevocably pronounced, everyone is silent, and the friends as well as the opponents of the measure unite in assenting to its propriety.” Although he exaggerates, the broad point remains true: the legitimising effect of public opinion is such that, other things being equal, majority support tends to amplify itself. Even if I have doubts about gay marriage, the fact that most of my countrymen are on the other side weakens my resolve and impels me to acknowledge the legitimacy of their view. The difference between support at, say, 55 per cent versus 45 per cent — that is, the different between majority and minority standing — is one of kind, not merely of degree. That is not to say that opposition evaporates or crawls under a rock when it loses majority standing. But its power and relevance are greatly reduced.

Still, those two somewhat mechanistic factors — demographics and the Tocqueville effect — beg the deeper question. True, younger people favour gay marriage; true, majorities amplify themselves. But why do the young feel as they do? Why has gay marriage crossed over to majority standing? Here we need to look inside the numbers, as it were, and understand the changes in moral thinking which drives them.


Changing Minds by Touching Hearts

In 2012, a public intellectual named David Blankenhorn, the founder and president of a pro-family think tank called the Institute for American Values (on whose board I sit), switched sides on gay marriage. His change of heart was of no mean significance. Beginning in the mid- 2000s, Blankenhorn had emerged as one of America’s two or three most articulate and thoughtful opponents of gay marriage. He wrote a book arguing that allowing gay couples to marry would push marriage dangerously far from its core task of uniting biological parents, especially fathers, with their children. In the important court case challenging the constitutionality of Proposition 8, California’s ban on gay marriage, he was the only expert witness to testify in favour of the ban. His reversal, coming on the heels of President Obama’s similar announcement, was a dramatic indication of the rethink which was going on.

Why the change of heart? Not just, or even mainly, because he had been argued out of his position. Rather, he had come to know gay people and gay couples, and had come to understand better their lives and aspirations. “I changed my opposition to gay marriage because of personal relationships,” he wrote in the Los Angeles Times. “Put simply, becoming friends with gay people who were married or wanted to get married led me to realise that I couldn’t in good conscience continue to oppose it.”

He spoke not just for himself but for millions. When Pew asked people, in 2013, why they had changed their minds on gay marriage, the response they most often volunteered was that they know someone who is gay. Today, Pew finds, 87 per cent report knowing someone who is gay or lesbian, and half have a close friend or family member who is gay. Where homosexuals used to seem a shadowy menace, they have come to be the couple next door, or the colleague at the office. It is hard to hate or fear people you know and like. The process of “coming out” has proved to be the most potent of all forms of egalitarian activism.

Not all Americans, of course, have come to see homosexuality as mundane or benign. But not all needed to. What mattered is the “swing vote”, the moderates who were never deeply attached to an anti-gay agenda on ideological or religious grounds, but who had not in the past been comfortable with the idea of homosexuality. Their crossing over has been the engine of rapid recent change; and it has been the personal, more than the political, which has led them across. Anyone who doubts this might look to the testimony of Obama himself, explaining his own decision, in May of 2012, to endorse gay marriage: “When I meet same-sex couples, and I see how caring they are, how much love they have in their hearts, how they’re taking care of their kids — when I hear from them the pain they feel that somehow they are still considered less than full citizens when it comes to their legal rights — then, for me, I think it just has tipped the scales in that direction.”

This is not to say that ideology and principle play no role. Having gay friends and family opens the mind to a new attitude, removing a wall of visceral aversion. Argumentation then begins to matter.

Intellectually, a kind of pincer movement occurred. On the one side, by the early 2010s it was becoming clear that the arguments against gay marriage were losing traction. I believe the reason was that opponents could never make their central claim stand up, because they could never offer a plausible reason why allowing gays to marry would damage straight families. In any event, by about 2010 opponents were pivoting away from opposing gay marriage on the merits, and toward a suite of secondary arguments which had less to do with marriage itself than with knock-on political effects: most commonly, that acceptance of gay marriage would lead to diminution of opponents’ religious liberty.

The fallback positions are too little, too late. Americans believe, correctly, that they can have gay marriage and religious liberty. Moreover, same-sex marriage has been in effect in Massachusetts since 2004, with no visible harm to anyone. Dire predictions have become untenable. Among “grass tops” leaders, and increasingly among grassroots swing voters, the case against gay marriage has stopped making sense.

Even as the objections lost ground, another set of arguments, and another style of argumentation, began to win converts. In America, same-sex marriage has always merged two distinct currents of support. One is egalitarian and rights-based: denying gay couples the opportunity to marry is a violation of equal rights. For years, this was the current which gay activists themselves emphasised — generally to poor effect in state and national politics. When asked to choose between abstract fairness and, say, the welfare of children and families, the swing vote went for family values every time.

The other current, by contrast, is communitarian and responsibility-based. This second strand emphasises that gay couples are fighting not to demean or defy bourgeois norms but to conform to them; that they are not just demanding rights but requesting responsibilities, to each other and their communities. As the writer Nathaniel Frank put it, in the Los Angeles Times:

Marriage is about a couple’s intimate choices, yes, but it’s also about the interplay between public recognition and private feelings and behaviour. Internalising that the people around us, and the law of the land, acknowledge our commitments can help us remain steadfast when the going gets tough.

Looked at this way, marriage is not just a commitment between two people but a shared public identity. It is freely chosen but ultimately constricts an individual’s freedom in the interest of greater goods: that of the couple and that of their community and nation.

In other words, centrist Americans who looked at gay marriage began to see a conservative cause. They saw not an attack on family values but an embrace of them. In this light, opponents’ insistence that marriage is defined solely by gender difference and fertility, rather than by interpersonal commitment and social obligation, began to ring hollow. The “pro-family” knife began to cut the other way. In ballot campaigns, pro–gay marriage advertising began foregrounding straight couples praising the loving, stable gay couple next door, rather than talking heads and portentous announcers inveighing against unfairness. And so the pincers began to close. One side began losing its argument while the other found its voice.


A Moral Miracle

Still, all that said, we have not quite yet touched bottom. What is happening in the United States is not merely a rethinking of gay marriage. It is something broader and deeper, something which we gay Americans find ourselves observing with a combination of awe and joy and occasionally disbelief: a comprehensive reimagining of the country’s moral relationship with its gay and lesbian citizens.

To understand the tipping of the gay marriage issue, the best polling question to look at is not about marriage at all. It is this, asked by Gallup: “Do you personally believe gay or lesbian relations are morally acceptable or morally wrong?” In 2001, “morally wrong” held a 13-point advantage (53 to 40). In 2008, however, the lines converged. Since then they have crossed and never looked back. By 2013, 59 per cent of the public called gay or lesbian relations morally acceptable.

The belief that homosexuality is morally wrong undergirds the entire superstructure of stigma and discrimination. The decline of that belief spells, inevitably, the collapse of that superstructure. And, indeed, the latest Pew poll shows a collapse under way. Today well over half of Americans tell Pew they hold a favourable overall opinion of gay men and lesbians, where fewer than 40 per cent did as recently as 2003. In 2004, 60 per cent said they would be upset if their own child were gay or lesbian (in 1985 this number was nearly 90 per cent); now only 40 per cent say they would be unhappy. When the presumption of fundamental differentness and invidiousness dissipates, the system of policies and attitudes built around that presumption stops looking rational or defensible.

For one gay American — the author of this article — today’s sea-change is moving, almost overwhelming, to watch. There never really was a reasoned case against gay love for gay people, at least not once it became clear that gay people really exist, and are not just straights with a bad habit. Held up to the light of day, the idea that gay people were better off in lives of lonely celibacy (as if that were practical), or that we deliberately chose lives of rejection and hardship, or that we ought to channel our sexual impulses into rampant promiscuity and surreptitious liaisons rather than marriage and family — none of those ideas was ever rational or defensible. Until recently, however, most straight Americans never did bother examining their assumptions. They were content with platitudes and dogmas, not so much because they were malevolent as because they were morally lazy and had other things on their mind. “Homosexuals? What do they have to do with us?” When I first began speaking about gay marriage on radio programs, well-intentioned straights, many of them supportive of gay marriage, often called in to say, “With crisis X or problem Y facing the country, why are we wasting energy on this issue?” They seemed to think I should be glad that opposing my marriage wasn’t worth their time.

That disregard, above all, is what changed. The public began paying attention to the case that gay people were making. I increasingly found, in my appearances on talk radio and my email inbox, that Americans were wrestling with their consciences: wondering if, after all, they had missed something important. When persistently challenged, they chose, at last, not to be lazy. Partly, of course, this was because more people had gay friends and family. Partly it was because what gay advocates said began to make sense. Partly it was because Americans remain committed to their founding creed: All men are created equal.

At the end of the day, however, to me an element of mystery remains. America’s change of heart toward its gay citizens is the greatest awakening of mass conscience in the United States since the civil rights movement of the 1960s, but it was achieved with far less bloodshed and bitterness. It is born of persuasion and love, not violence and hate.

Witnessing this awakening has been the most exhilarating and humbling experience of my life. Explaining it completely is, perhaps, impossible. Or perhaps I just want completely explaining it to be impossible. It feels, after all, like a miracle.