THE POLYGAMY THREAT. Jonathan Rauch is all about gay marriage but says polygamy's no good because it will generate excess unmarried men who bring with them social destruction. This seems a little dubious to me. As things stand, there are excess unmarried women because there are more gays than lesbians, more men die young (war, crime, car accidents), and way more men are in jail. So polygamy wouldn't generate a significant quantity of excess males unless you really had a lot of polygamists.
That just seems unlikely to me. The current legal prohibition on polygamy lacks efficacy. Realistically, most people don't live like that because they don't want to. Modern economic conditions allow almost everyone in America to live well above a level of bare subsistence and afford women much more social and economic independence than existed in traditional societies where polygamy was the norm. However, since gay marriage is never going to go through if people think it will lead immediately to legal polygamy, it's probably good for prominent gay marriage advocates to write articles about how terrible polygamy is. Then we'll get gay marriage, and sometime later the prohibition on polygamy will probably be dropped and everything will work out fine in the end.
--Matthew Yglesias