All it really takes is a little whipsaw action, where people can never feel really secure in coming out of the closet, because Who Knows? The law might change again -- in such a climate it wouldn't matter so much if we have DADT: people will just be afraid to be seen as gay and they will shut the hell up.
Fur Shur. I expect a fair number of the gays in training to immediately come out so they can get a General Discharge now ~ in the future being gay will not be an excuse to drop out.
I hope the law can be changed back. But I seriously doubt that it can be.
The courts will rule that it is an established constitutional right. It was headed that way, anyway.
Until the courts are restored to their rightful position as the weakest of the three branches of government, there is no Constitution.