Not to mention that Mary Cheney is a well paid member of her father's campaign (working on gay outreach, IIRC -- that's a thankless job). She's NOT a private figure, nor is she being outed.
Sully's right for a change (he's often right on these issues, but not a lot else). The only reason it's offensive to mention Mary Cheney is because the Right thinks it's somehow shameful for her to be gay.
I think that exposes their bigotry, not Kerry's. I live in San Francisco. If someone's gay and it makes a difference in a conversation, we acknowledge they're gay and move on. I don't pretend my gay friends aren't gay. I don't pretend it's some kind of secret. I don't pretend that nasty legislation targeted at gay people doesn't affect them, my friends, those people, personally.
I do think that the Kerry-Edwards repeated mentionings of Mary Chaney are a hardball tactic intended to take advantage of the fact that a substantial part of the Republican base is homophobic and votes on that basis: the intended message is "You thought Chaney was on your side on social issues? Wrong -- his daughter's a [pick your slur] and he hasn't disowned her."
It's hardball, but I think it's legitimate for one reason -- that Kerry/Edwards aren't in any way trying to pick up the homophobic votes they're trying to take away from Bush/Chaney. The hypothetical bigot who will be disgusted by mentions of Mary Chaney still knows that Bush and Chaney are closer to him than Kerry and Edwards on gay issues -- he's not going to move to Kerry because he now thinks Kerry is the bigots' candidate, he may just stay home in disgust. And I have to admit that I'm not too upset by any tactic that discourages one-issue bigots from voting.
I posted before that I don't think there's anything wrong with K/E playing the Mary Cheney card, mainly because Dick Cheney played it first. But if a critical mass of prominent gay commentators denounced the tactic, then I would defer to them. To judge from Sullivan, who is probably the most Bush/Cheney friendly of that group, such a chorus is unlikely to materialize.
Regarding your followup post: Undeniably Kerry's mention of Mary Cheney had the effect of reminding homophobes that their hero's daughter is gay, and it is almost as undeniable that Kerry anticipated this effect. I don't think one can either reduce intent to effect, or completely absolve Kerry from benefitting from the GOP's bigotry.
One way of looking at this: suppose we're back in the 60s, and Mary Cheney, instead of being a lesbian, is married to a black man. Would it be somewhat devious for Kerry to congratulate Cheney for welcoming a black man into his family? Probably. But for the analogy to fully apply, the GOP would have to be pushing a constitutional amendment to ban interracial marriages. In such a case, focusing on the tactic obscures the enormity of what the other side is undertaking. The same holds true for Kerry's reference to Mary Cheney versus the GOP's attempt to make permanent second-class citizens out of gays and lesbians.
Using the Neocons position against them!
I think part of it is defensive. Bush has a long history of responding to questions about homosexuality by praising tolerance on the one hand, while pointing out that homosexual activists support his opponent on the other. (In the South Carolina primary, he defended his refusal to meet with the Log Cabin Republicans by claiming -- falsely -- that they had already endorsed McCain.) Bringing up Mary Cheney innoculates Kerry against the "I'm not saying there's anything wrong with it, but, boy, my opponent sure hangs out with a lot of gays" slur, while also making Bush's own use of homosexuality as a wedge issue look particularly bad, since he is essentially campaigning against his vice-president's daughter.
Here's the big question: is the BC04 campaign using Mary Cheney to do outreach to the gay community? Answer: yes. That pretty much renders all the right-wing commentariat huffing and puffing into just so much pissing in the wind. They are irked that KE04 cleverly took the legs out from under their implied "we hates faggotses" appeal to the fundamentalist mouthbreathers.
Kerry should have known that the Cheneys are ashamed of their gay-homosexual daughter--she wasn't even allowed on stage with every other member of the family at the Republican Convention.