If you click here, you'll be able to read about a challenge to the military's don't ask don't tell policy. The crux of the argument is that the policy denies military members "their rights to privacy, free speech and equal protection under the law," according to attorney Stuart Delery.
The policy states that military members can't ask about sexual orientation of military members. It also says that military members that come out of the closet to the military must be separated if they can't promise that they won't participate in homosexual activity anymore while serving.
Now, pardon me if I'm mistaken, but didn't Lawrence v. Texas invalidate laws against sodomy on grounds that homosexual behavior performed in private is a private affair? If that be the case, then there certainly is an argument that homosexuals should be able to participate in homosexual acts while in the military free of criminal penalty. The problem is that from what I understand, Lawrence was in his own house when the police entered on the weapons warrant, and many military members are in barracks, which are military. These military members cannot possess weapons in their barracks, despite a second amendment right to keep and bear arms. I can see a similar argument that says these member contracted with the military to obey military commands (lawful orders), and as such, they are obligated not to participate in acts the military disapproves of.
Freedom of speech: Members of the Military do not enjoy the same First Amendment right to Freedom of Speech that civilians enjoy. In Goldman v. Weinberger, 475 U.S. 503, 106 S.Ct. 1310 (1986), the Court determined that the military is given far greater deference than the civilian sector in regulating first amendment rights (in the instant case, religion) to foster instinctive obedience, unity, commitment and esprit de corps. See Id. at 507.
Equal protection: I don't mean to split hairs, but the military's ban on sodomy applies to heterosexual couples as well as homosexual couples. I don't think there's much to argue there.
There is a Vanderbilt Law Review article on point from 1998 that is worth looking at for you law students and Constitutional lawyers types out there, 51 VNLR 1093.
Now, my opinion on the matter. Right now, the general demeanor of the military is discomfort with homosexuals. I saw it while I was in the military and I hear and read about it outside of the military. This discomfort continues and will continue even if the Don't ask don't tell policy is reversed. That will result in another problem. Because of the underlying discomfort and hostility towards homosexuals, the military members in combat situations could be compromised. Someone might be less likely to protect a gay soldier next to him or her, or might be less likely to trust them (I couldn't suggest why, but it's possible). At any rate, the problem is that it would disrupt the ability for our forces to work cohesively at a time that we are fighting to defend our way of life. While I have no problems serving with gay military members, I can see this as a potential hazard. I would rather see our way through our current situation before adding to the mix anything that can disrupt the continuity.