In recent months there has been a good deal of discussion of the president’s apparent mendacity in his selling of the Affordable Care Act. “If you like your health care you can keep it,” the president repeatedly assured his fellow citizens while the law was pending before Congress. The roll-out of the law in late 2013, however, revealed that this promise was no good, and it is difficult to believe that the president was not aware of this even as he was making it. Because the use of dishonesty to win support for legislation is hardly compatible with the American promise of self-government, this issue has deserved all the attention it has gotten, and indeed it deserves even more.

Nevertheless, the sitting president’s efforts to achieve progress (as he understands it) by recourse to falsehoods should also lead us to probe more deeply and see the bigger, even more consequential falsehoods upon which liberalism has relied for the last two or three generations. With every step of the “progress” it has sought in recent decades, with every effort it has made to “free” us from some aspect of morality, liberalism has made an Obama-like assurance that has turned out to be wrong.

Five years ago, the president falsely told Americans, “If you like your health care plan, you can keep your health care plan.” For the last fifty years, liberalism as a movement of moral liberation has repeatedly assured Americans, “If you like your morality, you can keep your morality.” In both cases, the game is to promise a limited reform that will not seriously disturb the status quo while delivering changes that have revolutionary consequences.

The project began in the late 1960s and early 1970s, when liberalism embraced the sexual revolution. In place of traditional standards of sexual morality, which held that the proper expression of human sexuality was within marriage and with a view to the generation of new life, liberals began to preach a message of sexual liberation. In matters of sex, they announced, whatever is done between “consenting adults” is none of society’s business.

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The tradition had held that sexual conduct is properly governed by both procedural and substantive norms. The procedural norm was provided by consent: forcible sex was condemned as the crime of rape. But consent was not the only issue, because sex was not governed only by a procedural norm. A substantive norm was provided by marriage and procreation. Thus, according to the tradition, adults might consent freely to certain forms of sex—fornication, adultery, or sodomy, for example—that would nevertheless still be wrong because of their inconsistency with the substantive purposes of human sexuality. The sexual revolution sought to strip sex of its substantive norms and leave only the procedural norm in place. This was the effect of slogans affirming the legitimacy of anything “consenting adults” might do.

As this kind of thinking was put forward by a certain kind of liberal, thoughtful conservatives warned about its revolutionary consequences. The liberal claim—that consent is the only ethically relevant concern in relation to sex—has the potential to erode all traditional sexual morality and all legislation based upon it. If consent is all that is required, then fornication cannot be wrong, prostitution cannot be wrong, and homosexual intercourse cannot be wrong.

The sexual revolution could not have succeeded to the extent that it did—that is, the public could not have embraced the liberal reduction of sexual ethics to “consent”—unless these radical consequences were ignored or denied. Those who warned about the ultimate consequences were disregarded. No decisive cultural change, no radical alteration in the nation’s way of life, was in the offing: just a little “loosening up” with regard to sex. Such claims have been proven wrong: with regard to sexual morality, the America of 2014 would be unrecognizable to the America of 1964. If the liberals of that era did not lie about the consequences of what they were doing, they were not fully honest, either. Like an unscrupulous merchant, they did not fully inform their customers of all the consequences of what they were buying.

Perhaps, however, the liberals of that era did not acknowledge all the consequences of what they were doing because they themselves did not fully understand them. Many of the liberals of that era probably would have agreed, if pressed, that certain forms of sexual intercourse were improper whether or not they were consented to. With a residual decency that far exceeded their theoretical acuity, they probably took it for granted that certain forms of sex would remain outside the moral pale. For such liberals, rhetoric about “consenting adults” was probably intended to do no more than legitimize premarital sex. Such people were duping themselves as well as those upon whom they practiced such rhetoric, and therefore could not be accused of willful dishonesty. In any case, it is difficult to accuse a political movement of breaking faith over the course of two generations. Today’s sexual revolutionists may be the heirs of the liberals of the late 1960s and early 1970s predecessors, but they are not, for the most part, the same people.

Nevertheless, the same problem has repeated itself in more recent times, and over such a short period of time that it is hard to exonerate the left of willful duplicity. For example, when the Supreme Court, in Lawrence v. Texas (2003), struck down Texas’s statute prohibiting homosexual sodomy, the Court’s opinion—authored by Anthony Kennedy—went out of its way to assure the nation that the case had nothing to do with the question of same-sex marriage.

In dissent, Justice Scalia, seeing through the Court’s “bald disclaimer” to the actual tendency of its reasoning, bluntly told the country: “do not believe it.” Events shortly proved Scalia right. The ink was hardly dry on the Court’s opinion before state courts began lifting the reasoning of Lawrence and using it to invalidate state laws that defined marriage as a union between a man and a woman. And in 2013’s Windsor ruling, just ten years after his Lawrence disclaimer, Justice Kennedy himself showed his inclination to use Lawrence’s reasoning to move toward creating a right to same-sex marriage. It is difficult to avoid the conclusion that Lawrence was just one step in a larger project of sexual liberation by means of constitutional law, although Kennedy explicitly denied it at the time.

A similar lack of candor can be seen in the argument over same-sex marriage itself. One point commonly made by opponents of same-sex marriage is that the argument for it—an argument that typically appeals to the autonomy of love, and emphasizes the right to equal recognition for all forms of love—is indistinguishable from an argument for abolishing any objective definition of marriage. Accordingly, same-sex marriage could not be the stopping point of sexual liberation, which would then have to go on and demand a normalization of polygamy. The proponents of same-sex marriage typically responded to this argument by treating it as outlandish and acting as if no normal person could hold any such development in serious contemplation. Yet now that the Supreme Court seems to be on the verge of finding a right to same-sex marriage, some liberal activists are already beginning to argue for the legitimacy of polygamy—something the movement denied any interest in just a few years ago.

After polygamy, what will be liberalism’s new frontier of sexual liberation? Lowering the age of consent? Abolishing laws against prostitution? Normalization of adult incest? No one can say.

It is both troubling and galling to think that we are now at the end of a fifty-year fraud that has been perpetrated on us in relation to some of the most important things in human life. But it is even more troubling to realize that we may not in fact be at the end but still in the middle of that great fraud, to realize that there are still more consequences to face, now hidden and even denied but nevertheless approaching inexorably with the unfolding of the logic of sexual liberation. The moral mugging is not over but still going on.

No one can say where sexual liberation will stop, because liberalism will not be honest with the country about its ultimate ends, and may not even know those ends itself. This makes contemporary sexual liberalism a frightening spectacle, and Americans ought to reexamine their commitment to it. The unchecked progress of sexual liberalism means that we cannot say what kind of moral culture our children will inhabit as adults or, accordingly, what kind of moral culture will form our grandchildren. No responsible person can support such a movement.