We are barely five years past Lawrence v. Texas, but Conor Friedersdorf apparently can think of no legitimate argument against gay marriage and certainly will cede nothing to Mona Charen.

Is there anyone under 30 who opposes gay marriage? Is the passage of five years sufficient to deprive Justice Scalia’s dissent of intellectual respectability?

I’m still thinking about Roy Moore’s ruling in Ex Parte H.H.

UPDATE: In a follow-up, Friedersdorf says, “my support for gay marriage is so inextricably tied to my conservatism.” And the only wonder is that Willmoore Kendall, Russell Kirk and Richard Weaver didn’t beat him to it.

If it is still permissible to disagree that conservatism “inextricably” requires what Friedersdorf says it does, how did we get here? The answer can be boiled down to one word, equality.

Are men and women equal in the fullest sense of the word? If so, then equality implies fungibility — the two things are interchangeable and one may be substituted for the other in any circumstance whatsoever. (La mort à la différence!) Therefore, it is of no consequence whether I marry a woman or a man.

The fantastical project of yesterday, which was mentioned only to be ridiculed, is to‑day the audacious reform, and will be tomorrow the accomplished fact.

This is why so many of those who would defend traditional marriage find themselves unable to form a coherent argument, because traditional marriage is based on the assumption that men and women are fundamentally different, and hence, unequal. Traditional marriage assumes a complementarity of the sexes that becomes absurd if you deny that “man” and “woman” define intrinsic traits, functions, roles.

To declare men and women unequal, however, puts one outside the law — you are guilty of illegal discrimination if you say that there is any meaningful difference between men and women. Yet if you refuse to argue against sexual equality, you cannot argue effectively against gay marriage, and find yourself subjected to lectures about “accessing the positive social norms” with nothing important to say in reply.