Here she is speaking, from a position opposed to gay marriage, about criticisms of that position:
The best counterargument is the same as the best counterargument on all gay-marriage topics: “This isn’t just about gay marriage but about a whole panoply of prior changes, most of which have obvious good qualities as well, so you’re not seeking status quo so much as rollback.” ...Her other comments ad loc are incisive, quite wide-ranging, and well-taken; and some of the links are fascinating. At the end of the day, though, I'm still confused about how she can reconcile herself to a group running an ad that she herself describes as fearmongering, and as “really, really cheesy”.
I see the force of that argument, and of course I acknowledge that there’s no way we would be having this conversation without the prior cultural changes which led to e.g. laws against discrimination based on sexual orientation. For that matter, every single day I take advantage of the cultural changes which have made it possible for me to be an out lesbian while facing very limited explicit hostility.
But I still disagree that gay marriage is only a trivial turn of the ratchet (do ratchets turn?? I’m really not the home-improvement kind of dykey!), a mere formality, or something you can only worry about if you also reject all of the prior cultural moves which brought us here. I think prudence can allow you to draw a line, and frankly, gay marriage is a really obvious place for that line. Gay marriage is a big deal for the same reasons given by its supporters!--it is a real change in the culture, a deeply significant change, and a change with far-reaching public implications. I don’t think you can write paeans to marriage as a public and cultural status, then turn around and say that gay marriage will have very limited public effects. Marriage isn’t designed to have limited public effects.
Because belonging to a lobby group or a movement is not the same as belonging to a church. I've elsewhere posted in admiration of Ms Tushnet's Catholicism and the resources it gives her, and the home it provides her; and for another example, the USCCB's Pastoral Message to Parents of Homosexual Children, also cited by Tushnet, is a good advertisement for the Catholic Church: one could disagree with the position, and still respect the practical advice; one could disagree with the advice, and still admire the humanity and maturity of its conception. I understand how one could disapprove of the church in other ways, but value the tradition that makes this sort of thing possible: I understand that because it's pretty much my own position. A propos of this, a friend pointed out that a church is not meant to be admired from a safe distance ... which is a good point, so let me put it this way: I can see how, being a Catholic, one might choose to stay one; I can see how, having become a Catholic, one might judge it to have been a good choice, any drawbacks apart.
But a lobby group or a movement is not like that. Achieving an effect, pushing a point of view or policy, effecting a particular change in society, is the point of the endeavour. That's what a lobby is about: there is no other “there” there. So when a lobby comes up with a cheesy, fearmongering advertisement, it is reasonable to view it as essentially discrediting, in a way that it's not when a person does something wrong, or a country does something objectionable, or a church says something silly. If a lobby is in the business of saying silly things, or saying things in an objectionable way, isn't it Just Bad?
Which brings me back to my own local concerns. One of my criticisms of the evangelical church, at least in this town, is related: I think it's confused about whether it's a movement or a church --- even worse, whether it's an insurgent movement or The Church, simpliciter. This has all sorts of implications for how one views membership, duty, loyalty, and the ethical position of both individuals and officials: I take a rather different view, for example, of a minister on the one hand, and a cadre of a movement on the other; if they are the same person, there is potentially a serious problem. But that is really a matter for its own post, on another occasion.
 I can't seem to link to individual posts there. The ones I mean are from April 2009: scroll down to Wednesday, April 15, and look for "POLITICS AND THE ENGLISH LANGUAGE" and “'When I make a word do a lot of work like that,' said Humpty Dumpty, 'I always pay it extra.'".
 Short version: I am a conservative Christian, in the Anglican tradition (and happy to be so), I live in Sydney, and while it would be misleading to call me an evangelical I'm probably more like that than anything else; and I was taught and trained by evangelicals, and I have friends in that ministry. And yet I find the public stance of the Sydney Diocese, in particular its official media presence, absolutely unbearable.