Stanley Kurtz has been a busy guy. This article surveys the European and American sociological literature on gay marriage, concluding:
Shifting to a broad “menu” of experimental family forms may feel liberating to some, but it is really a recipe for thinning out society’s commitment to children. Each unconventional experiment reinforces the others, ultimately yielding a significantly less stable family regime. Which is to say, gay marriage undermines marriage. Or, as we say in some precincts, the “queering of the social calls into question the normativity and naturalness of heterorelationality.”
This one focuses on polygamy and polyamory, raising serious questions as to whether those marital forms are consistent with democracy (I’d say democratic republican self-government).