One of the key myths of the American Catholic imagination is this: After 200 years of fighting against public prejudice, Catholics finally broke through into America’s mainstream with the 1960 election of John F. Kennedy as president. It’s a happy thought, and not without grounding. Next to America’s broad collection of evangelical churches, baptized Catholics now make up the biggest religious community in the United States. They serve in large numbers in Congress. They have a majority on the Supreme Court. They play commanding roles in the professions and in business leadership. They’ve climbed, at long last, the Mt. Zion of social acceptance.

So goes the tale. What this has actually meant for the direction of American life, however, is another matter. Catholic statistics once seemed impressive. They filled many of us with tribal pride. But they didn’t stop a new and quite alien national landscape, a “next America,” from emerging right under our noses.

While both Barna Group and Pew Research Center data show that Americans remain a broadly Christian people, old religious loyalties are steadily softening. Overall, the number of Americans claiming no religious affiliation, about 16 percent, has doubled since 1990. One quarter of Americans aged 18-29 have no affiliation with any particular religion, and as the Barna Group noted in 2007, they “exhibit a greater degree of criticism toward Christianity than did previous generations when they were at the same stage of life. In fact, in just a decade . . . the Christian image [has] shifted substantially downward, fueled in part by a growing sense of disengagement and disillusionment among young people.”

Catholic losses have been masked by Latino immigration. But while 31 percent of Americans say they were raised in the Catholic faith, fewer than 24 percent of Americans now describe themselves as Catholic.

These facts have weight because, traditionally, religious faith has provided the basis for Americans’ moral consensus. And that moral consensus has informed American social policy and law. What people believe—or don’t believe—about God, helps to shape what they believe about men and women. And what they believe about men and women creates the framework for a nation’s public life.

Or to put it more plainly: In the coming decades Catholics will likely find it harder, not easier, to influence the course of American culture, or even to live their faith authentically. And the big difference between the “next America” and the old one will be that plenty of other committed religious believers may find themselves in the same unpleasant jam as their Catholic cousins.

At first hearing, this scenario might sound implausible; and for good reason. The roots of the American experience are deeply Protestant. They go back a very long way, to well before the nation’s founding. Whatever one thinks of the early Puritan colonists—and Catholics have few reasons to remember them fondly—no reader can study Gov. John Winthrop’s great 1630 homily before embarking for New England without being moved by the zeal and candor of the faith that produced it. In “A model of Christian charity,” he told his fellow colonists:

We are a company professing ourselves fellow members of Christ . . . That which the most in their churches maintain as truth in profession only, we must bring into familiar and constant practice; as in this duty of love, we must love brotherly without dissimulation, we must love one another with pure heart fervently. We must bear one another’s burdens. We must look not only on our own things, but also on the things of our brethren . . . We must be willing to abridge ourselves of our superfluities, for the supply of others’ necessities. We must uphold a familiar commerce together in all meekness, gentleness, patience and liberality. We must delight in each; make others’ conditions our own; rejoice together, mourn together, labor and suffer together, always having before our eyes our commission and community in the work, as members of the same body. So we will keep the unity of the spirit in the bond of peace.

Not a bad summary of Christian discipleship, made urgent for Winthrop by the prospect of leading 700 souls on a hard, two-month voyage across the North Atlantic to an equally hard New World. What happened when they got there is a matter of historical record. And different agendas interpret the record differently.

The Puritan habits of hard work, industry and faith branded themselves on the American personality. While Puritan influence later diluted in waves of immigrants from other Protestant traditions, it clearly helped shape the political beliefs of John Adams and many of the other American Founders. Adams and his colleagues were men who, as Daniel Boorstin once suggested, had minds that were a “miscellany and a museum;” men who could blend the old and the new, an earnest Christian faith and Enlightenment ideas, without destroying either.

But beginning in the nineteenth century, riding a crest of scientific and industrial change, a different view of the Puritans began to emerge. In the language of their critics, the Puritans were seen as intolerant, sexually repressed, narrow-minded witch-hunters who masked material greed with a veneer of Calvinist virtue. Cast as religious fanatics, the Puritans stood accused of planting the seed of nationalist messianism by portraying America as a New Jerusalem, a “city upon a hill” (from Winthrop’s homily), with a globally redemptive mission. H.L. Mencken—equally skilled as a writer, humorist and anti-religious bigot—famously described the Puritan as a man “with the haunting fear that someone, somewhere, may be happy.”

In recent years, scholars like Christian Smith have shown how the intellectual weakness and fierce internal divisions of America’s Protestant establishment allowed “the secularization of modern public life as a kind of political revolution.” Carried out mainly between 1870 and 1930, this “rebel insurgency consisted of waves of networks of activists who were largely skeptical, freethinking, agnostic, atheist or theologically liberal; who were well educated and socially located mainly in the knowledge-production occupations, and who generally espoused materialism, naturalism, positivism and the privatization or extinction of religion.”

This insurgency could be ignored, or at least contained, for a long time. Why? Because America’s social consensus supported the country’s unofficial Christian assumptions, traditions and religion-friendly habits of thought and behavior. But law—even a constitutional guarantee—is only as strong as the popular belief that sustains it. That traditional consensus is now much weakened. Seventy years of soft atheism trickling down in a steady catechesis from our universities, social-science “helping professions,” and entertainment and news media, have eroded it.

Obviously many faith-friendly exceptions exist in each of these professional fields. And other culprits, not listed above, may also be responsible for our predicament. The late Christopher Lasch argued that modern consumer capitalism breeds and needs a “culture of narcissism”—i.e., a citizenry of weak, self-absorbed, needy personalities—in order to sustain itself. Christian Smith put it somewhat differently when he wrote that, in modern capitalism, labor “is mobile as needed, consumers purchase what is promoted, workers perform as demanded, managers execute as expected—and profits flow. And what the Torah, or the Pope, or Jesus may say in opposition is not relevant, because those are private matters” [emphasis in original].

My point here is neither to defend nor criticize our economic system. Others are much better equipped to do that than I am. My point is that “I shop, therefore I am” is not a good premise for life in a democratic society like the United States. Our country depends for its survival on an engaged, literate electorate gathered around commonly held ideals. But the practical, pastoral reality facing the Gospel in America today is a human landscape shaped by advertising, an industry Pascal Bruckner described so well as a “smiling form of sorcery”:

The buyer’s fantastic freedom of choice supposedly encourages each of us to take ourselves in hand, to be responsible, to diversify our conduct and our tastes; and most important, supposedly protects us forever from fanaticism and from being taken in. In other words, four centuries of emancipation from dogmas, gods and tyrants has led to nothing more nor less than to the marvelous possibility of choosing between several brands of dish detergent, TV channels or styles of jeans. Pushing our cart down the aisle in a supermarket or frantically wielding our remote control, these are supposed to be ways of consciously working for harmony and democracy. One could hardly come up with a more masterful misinterpretation: for we consume in order to stop being individuals and citizens; rather, to escape for a moment from the heavy burden of having to make fundamental choices.

Now, where do Catholics fit into this story?

The same Puritan worldview that informed John Winthrop’s homily so movingly, also reviled “Popery,” Catholic ritual and lingering “Romish” influences in England’s established Anglican Church. The Catholic Church was widely seen as Revelation’s Whore of Babylon. Time passed, and the American religious landscape became more diverse. But the nation’s many different Protestant sects shared a common, foreign ogre in their perceptions of the Holy See—perceptions made worse by Rome’s distrust of democracy and religious liberty. As a result, Catholics in America faced harsh Protestant discrimination throughout the 18th and 19th centuries. This included occasional riots and even physical attacks on convents, churches and seminaries. Such is the history that made John F. Kennedy’s success seem so liberating.

The irony is that mainline American Protestantism had used up much of its moral and intellectual power by 1960. Secularizers had already crushed it in the war for the cultural high ground. In effect, after so many decades of struggle, Catholics arrived on America’s center stage just as management of the theater had changed hands -- with the new owners even less friendly, but far shrewder and much more ambitious in their social and political goals, than the old ones. Protestants, Catholics and Orthodox, despite their many differences, share far more than divides them, beginning with Jesus Christ himself. They also share with Jews a belief in the God of Israel and a reverence for God’s Word in the Old Testament. But the gulf between belief and unbelief, or belief and disinterest, is vastly wider.

In the years since Kennedy’s election, Vatican II and the cultural upheavals of the 1960s, two generations of citizens have grown to maturity. The world is a different place. America is a different place—and in some ways, a far more troubling one. We can’t change history, though we need to remember and understand it. But we can only blame outside factors for our present realities up to a point. As Catholics, like so many other American Christians, we have too often made our country what it is through our appetite for success, our self-delusion, our eagerness to fit in, our vanity, our compromises, our self-absorption and our tepid faith.

If government now pressures religious entities out of the public square, or promotes same-sex “marriage,” or acts in ways that undermine the integrity of the family, or compromises the sanctity of human life, or overrides the will of voters, or discourages certain forms of religious teaching as “hate speech,” or interferes with individual and communal rights of conscience—well, why not? In the name of tolerance and pluralism, we have forgotten why and how we began as nation; and we have undermined our ability to ground our arguments in anything higher than our own sectarian opinions.

The “next America” has been in its chrysalis a long time. Whether people will be happy when it fully emerges remains to be seen. But the future is not predestined. We create it with our choices. And the most important choice we can make is both terribly simple and terribly hard: to actually live what the Church teaches, to win the hearts of others by our witness, and to renew the soul of our country with the courage of our own Christian faith and integrity. There is no more revolutionary act.

Charles J. Chaput is the archbishop of Denver.