Hardly a week passes without a major story documenting the march of homosexuality into the American mainstream. In the latest development, more than 100 prominent members of the GOP — a party that less than a decade ago spearheaded an effort to pass a constitutional amendment banning gay marriage — have signed a legal brief urging the Supreme Court to declare that gay people have a constitutional right to marry. This follows on the heels of news that the Obama administration has filed its own brief with the high court in favor of overturning the 1996 Defense of Marriage Act, which defines marriage in federal law as a union between a man and woman.

We are living through an astonishing cultural and political sea change — one that looks likely to expand significantly the frontiers of liberty and equality in the United States. That's something that rapidly expanding numbers of Americans are prepared to accept and even applaud. But not all of them. A significant number of our fellow citizens (between a third and a half) affirm traditionalist religious views about sex and marriage that preclude them from embracing the new order. Some of these traditionalists have begun to worry — and not for frivolous reasons — that the widespread recognition of same-sex marriage will be followed by a public campaign to stamp out their dissent from the emerging pro-gay consensus.

Those who care about the fate of freedom in the United States must not allow this to happen.

Opponents of gay marriage — as well as a range of fair-minded writers and legal scholars — foresee several possible assaults on religious freedom. Some predict that clergy and religious communities will be forced to solemnize same-sex marriages. Others claim that preaching against homosexuality could be prosecuted under hate-crime statutes. Still others envision hospitals and universities affiliated with traditionalist religious institutions running into legal trouble for staying true to their principles and beliefs by refusing to recognize the marriages of same-sex couples. Finally, many traditionalists anticipate a future in which the nation's public schools treat the history of discrimination against homosexuals and their eventual acceptance into the mainstream of American life as perfectly analogous to the story of racial discrimination and the triumph of the movement for black civil rights. In that case, the government would be actively working to undermine the sexual morality that traditionalists wish to pass on to their children.

Many supporters of gay rights will no doubt say that this is precisely what the government should be doing, since it has as much of an interest in weakening homophobia as it does in weakening racism. But this fails to acknowledge the very different roles of race and gender in the Abrahamic religious traditions. While various religious texts have been used to justify racism and slavery over the centuries, these texts do not command adherents to adopt these practices in the way that they appear to command obedience to a series of strict teachings about gender roles and sexual propriety. Which is to say that the attempt to use the public schools to stamp out homophobia is a far more profound challenge to the integrity of traditionalist religious beliefs than is the effort to drive out racism. If we want to avoid provoking a mass exodus of religious traditionalists from the public schools (and we should certainly want to avoid it), we must tread very cautiously in these matters, restraining the urge to educate traditionalists away from their deeply held religious convictions.

But we must also go further, taking concrete, legal steps to guarantee that the religious freedom of traditionalists is recognized and protected. Why? Because the United States is a nation dedicated to the ideal of freedom — and religious freedom is, in several senses, the first freedom. The Puritans settled New England to establish a political order that would guarantee religious liberty. Nearly 170 years later, James Madison began the Bill of Rights with a robust defense of religious freedom. To this day, the right of individuals to practice their faith — and to pass it on to their children as they see fit, usually by participating in the life of privately organized religious communities and institutions — serves as a foundational element of the nation's civic order.

It is our commitment to protecting individual rights that enables us to live together in relative peace, despite our deep disagreements about how to answer ultimate questions — including the question of whether God exists, and if He does, how He wants us to live. When the government denies traditionalists the right to answer these questions as they wish, it uses illiberal means to impose liberal ends. And that should be considered unacceptable.

In practical terms, this means that we need to build on what states such as Connecticut and New Hampshire have already begun to do: include passages or amendments in same-sex-marriage legislation that explicitly define and protect the religious freedom of sexual traditionalists. This doesn't mean that traditionalists should get their way on every matter; the law traditionally limits claims to religious freedom when members of a religious community provide services outside their faith tradition (like adoption or hospital care) or enter the commercial marketplace (by, say, leasing a catering hall for wedding receptions). In such cases, religious traditionalists might be forced to recognize the legal validity of same-sex marriages (while presumably continuing to judge them, on a personal level, as morally and spiritually null and void). But on the all-important matter of religious freedom (in both speech and practice), we need to write laws and regulations in such a way that they unambiguously protect the right of traditionalists to preach their beliefs about the evils of homosexuality and to pass those beliefs on to their children.

This may make some liberals uncomfortable. But civically speaking, it is no less important than advocating for homosexual rights. Politics in a free society shouldn't be used to stamp out the views of those who dissent from prevailing opinion. It should be used to defend the rights of the dissenters.

Damon Linker is a senior writing fellow at the University of Pennsylvania, a contributing editor at The New Republic, and the author of The Theocons and The Religious Test. You can follow him on Twitter: @DamonLinker.