The Fourth of July is around the corner, with the delightful prospect of fireworks, town parades and family cookouts in store.

Independence Day 2013 will also mark the close of the U.S. bishops-organized "Fortnight for Freedom." And, for some Catholics, the holiday celebrations will be dimmed by a sense of unease regarding the nation’s moral and political direction.

Such reflections are stirring up doubts about whether the speech and practices of religious believers will be welcomed in the public square in the years to come.

What does it mean to be an American, and how should U.S. citizens work to strengthen the American experiment in ordered liberty that made our republic a beacon for the world?

Today, the answers to such questions are by no means obvious. Take, for example, the polarized debate on same-sex "marriage." Advocates of "marriage equality" frame their cause as the final chapter in the nation’s forward march toward equality for all — a stance that raises questions about the moral credibility of those who resist any redefinition of marriage.

"Our journey is not complete until our gay brothers and sisters are treated like anyone else under the law," President Obama stated during his 2013 inaugural address.

So are U.S. Catholics who cling to Church teaching on marriage un-American — or are they actually fighting a lonely but necessary battle to keep the republic on course?

The issue today is: "Who can give an account of the nobility of the American experiment?" George Weigel observed during a June 7 address at the Portsmouth Institute’s conference on "Catholicism and the American Experience." He urged his audience to tap into the Church’s rich trove of moral and social teaching to help correct the nation’s truncated view of freedom as the fulfillment of individual desires.

In response to those who assert that sexual expression is a primary American value, Weigel pointed to the lyrics of America the Beautiful that beseech God’s help to "confirm" the nation’s "soul in self-control" and its "liberty in law."

Church teaching remains compatible with the Founding Fathers’ vision, he stressed. "There are transcendent moral truths inscribed in the world that we can know by reason," said Weigel, articulating the natural-law precept that once anchored the American experiment in ordered liberty and still inspires the U.S. bishops’ intervention in policy debates.

Yet, if some 21st-century Catholics criticize the bishops’ failure to secure broad respect for religious liberty, the natural law and the need for Christian virtue, the past century reminds us that the Church has often adopted an unpopular but prophetic role in a Protestant culture and a capitalist economy. There have been "labor priests" who defended unions and the right to strike and Catholic pro-life activists who launched the right-to-life movement after the U.S. Supreme Court legalized abortion.

Past generations of U.S. Catholic leaders challenged the status quo, even as they created a parallel system of Church-affiliated schools, hospitals and charities. An extraordinary cohort of men and women, lay and religious, educated and cared for the poor and the unwanted. They attracted unlikely converts, like Dorothy Day, a former radical and atheist who later converted and founded the Catholic Worker movement.

"Can you think of a word that describes a person who refused to pay taxes, didn’t salute the flag, never voted, went to prison time and again for protests against war and social injustice, who spoke in a plain and often rude way about our ‘way of life’?" asked Day biographer Jim Forest during his address at the Portsmouth Institute.

Day became a Catholic, Forest said, after, "rosary in hand, she prayed her way through her out-of-wedlock pregnancy; prayed her way through the Baltimore Catechism; prayed her way through the collapse of her relationship with her unborn child’s father; prayed her way to her daughter Tamar’s birth and baptism, and then to her own baptism; prayed her way through the incomprehension of her atheist friends who regarded all religion as snake oil; prayed her way through a good deal of loneliness."

Dorothy Day’s pilgrimage was unusual. But her story offers an engaging reminder about generations of American Catholic activists who saw no need to choose between the cause of social justice and a firm adherence to the beliefs and practices of their faith.

Almost a century after Day was baptized, the Church continues its prophetic role. And, once again, the impact will be felt not only in the Church, but in mainstream American culture.

Jesuit John Courtney Murray, in his landmark We Hold These Truths: Catholic Reflections on the American Proposition, cautioned his fellow citizens to never become complacent about the survival of the republic.

"Neither as a doctrine nor as a project is the American Proposition a finished thing. Its demonstration is never done once for all; and the Proposition itself requires development on penalty of decadence," wrote Murray.

The vital work of strengthening this legacy, Weigel predicted, will be advanced by an emerging generation of Catholic leaders capable of reframing the public debate on the role and limits of the state and the duties and rights of citizens. More importantly, they will be leaders who know that effective evangelization requires nothing less than "radical discipleship," he said. The Church must offer a compelling alternative to "the loneliness of so much of the postmodern world."

Said Weigel, "The race is on as to which train pulls ahead on these parallel tracks."