Fafblog, of course, does it better than we could:

Dick and Lynne Cheney are right to be outraged [. . . ]. And this outrage comes not because they feel that homosexuality is shameful or icky or full of cooties. It is because they know that the greatest shame one can bring to a lesbian is to note their existence. Before John Kerry’s terrible words, Mary Cheney only had to be gay to her family, her friends, the Coors Corporation, the staff of Bush/Cheney Re-Elect, and the gay community at large to whom she acted as a liason. But John Kerry made her gay to the entire world, effectively making her more gay than ever before. (Emph. in original)