David Link gets inside McCain's head:
McCain cannot seem to accept that the world might have changed around him, and that the transcendent importance he attributes to sexual orientation isn’t so widely shared any more. And the context of the hearings couldn’t better illustrate the disproportion of the obsession with homosexuality. However important or not DADT is, is funding the nation’s entire military really the secondary consideration?
Yes, attaching repeal to the funding bill was a political move big surprise. But it’s political mostly in the sense that it illuminates the self-indulgence of politicians who are hellbent on catering to a dying prejudice.
To McCain, it is the status quo the institutionalization of prejudice that is transcendently important. He is defending DADT as if it were a principle, rather than a political compromise that no one liked in the first place, but everyone could agree on in order to extricate Bill Clinton from his failed political promise to gays.