"Both of the foregoing proposals – a limited right of self-defense and a limited right to own or possess long guns – lack any direct connection to the military focus of the Second Amendment. My final proposal would address that deficiency. Even if we do not share the Founders’ skepticism of standing armies, we may well sympathize with the ideal of the citizen-soldier in the following sense: We are rightly concerned by large gaps between martial and civilian values. Nuremberg and My Lai teach that notwithstanding the importance of military discipline, the duty to follow orders does not excuse members of the armed services of their duty to follow minimal rules of human decency. The Iran-Contra affair provides a warning about how ready military officials may be to execute policy contrary to law if they are convinced that the civil authorities will turn a blind eye. The ideal of a citizen-soldier in the sense of a service member who is both of the people and subject to civilian control is thus very much a modern ideal.
"And how does the Second Amendment speak to this ideal in modern times? By providing a right of the people to keep and bear arms – that is, a right to serve in the military. Of course the government need not accept anyone who wishes to serve in the military. Exclusions based on physical fitness, military need, criminal record, and so forth, would be perfectly appropriate. But wholesale exclusions based on stereotypical assumptions would not be consistent with the ideal of armed forces drawn from “the people.” On this reading, the most substantial effect of the Second Amendment today would be to invalidate official military discrimination on the basis of sex and sexual orientation.
"This proposal is not nearly as odd as it at first appears. Its great virtue is its synthesis of the Founding and Reconstruction as those periods are now understood."
You can find Professor's Dorf's rather lengthy Law Review article on ssrn.com.
Moving right along, in the context of the due process right to liberty where its exercise is fundamental to the person, the case for the extension of this precept to gays in the military would be stronger if the US were like Israel, where just about every Jew (at least male Jew) serves in the military, and the lack of such service is a hinderance to one's future career. Here, few of us serve in the military, and thus to suggest such service represents an exercise of a right fundamental to the person is a bit of a stretch. Most of us seem to get along just fine in living out our "fundamental personage" without having served in the military. But that doesn't mean some SCOTUS court won't go there, to the extent the Second Amendment is found wanting in that regard despite Dorf's arguments.
And there you have it. Isn't the law fun? And to think some of us get paid the big bucks to practice it. It is almost a scandal.