The only issue is whether it prohibits it. It doesn't. Nobody ever thought that that's what it meant. Nobody ever voted for that. If the current society wants to outlaw discrimination by sex, hey we have things called legislatures, and they enact things called laws.
These views are not new; Scalia has also dismissed the idea that the 14th Amendment might protect against gender discrimination in his dissent in U.S. v Virginia. Scalia's arguments, in addition to having odious consequences, provide an example of the extent to which originalist rhetoric conceals choices that are political, not legal.
Scalia has never been consistent about applying the principles expressed above. Nobody who voted for the Fifth or 14th Amendments thought that they were prohibiting affirmative action, and yet Scalia has found that both amendments prohibit affirmative action in virtually all circumstances. Scalia also believes that Brown v. Board was correct, although very few of the persons who voted in favor of the proposal or ratification of the 14th Amendment believed that it prohibited racial segregation. When the originalist principles outlined above clash with (rather than reinforce) his political preferences, Scalia has no problem ignoring them.
Scalia's answer when it comes to gender? That while the framers and ratifiers of the 14th Amendment did not think they were outlawing affirmative action or school segregation, they did think they were outlawing racial discrimination; they didn't specifically discuss gender discrimination. The problem with this response is that Scalia's choice to stop at this particular point on the ladder of abstraction is completely arbitrary. Scalia has already made clear in other cases that he doesn't think that the concrete expectations of framers or ratifiers are binding. And the 15th Amendment demonstrates that the framers of the 14th could have limited the equal protection clause to racial discrimination, but they did not. So what basis does Scalia have for being certain that the 14th Amendment permits gender discrimination?
He doesn't. Scalia's belief that the 14th Amendment does not prohibit gender discrimination is a political choice in no way compelled by the text of the Constitution.
-- Scott Lemieux