Polygamy is Legal

In the post Should the State Proscribe Non-Marriages we looked at the historical role of marriage. The major argument of that piece was that, if society does not prohibit living arrangements that are like marriages in all aspects other than legal status, then there really is no point in marriage at all. That argument was then taken to apply to non-standard living arrangements as well. Specifically, polygamy. All states ban polygamy, but because there is no enforcement against relationships that are practically but not legally polygamy, there is effectively no ban on polygamy.

Today I see a video on facebook about a couple who has found a way to incorporate the major legal benefits of marriage into their polygamous relationship. For all practical purposes, this man has two wives. He is now divorcing his first wife -- who, as mother, will retain legal status over her children -- and marrying the new wife, who will thus attain legal status over the children. It's not quite pure polygamy. If he has a kid with the new wife, then the original wife will not have legal status over those children. Also, the original wife has given up her ability to sue for divorce and must file her taxes independently. But that's about it. As the family is now, they now have legal status approximately equivalent to a polygamous family. In whatever state they are living in, the law against polygamy is but a quaint relic.

This video was posted by someone who was actually praising such a progressive arrangement. There is a certain perspective where one could support this, which is by completely ignoring all social and historical contexts. If you perform your analysis in the universe of just those 3 individuals, then there is little to object to. Of course the man will prefer two wives if he can swing it. And if the wives are happy with the arrangement, then who's to judge? It's all very easy and happy if you refuse to ask more difficult contextual questions such as: why is it that nearly all stable societies seem to adopt monogamy? Note that the context-less opinion is really the libertarian argument. Are these people directly infringing on anyone else's liberties? No. Are they following the letter of the law? Yes. Then it's perfectly libertarian friendly! There is some difference between the liberals who advocate for these things and the libertarians why merely find it acceptable. Libertarian opinions, wrong as they often are, come from principles. Liberal support for this type of arrangement is not because it satisfies the libertarian tenets of amoral legal transactionalism (although they'll appropriate those arguments to suit their ends) or because it satisfies any formal liberal principles (of which there are none). The liberals love it because they love anything that bucks traditional western culture, and particularly anything they think will really rub conservatives' noses in it.

TL;DR
Polygamy is banned yet permitted in the US. Libertarians are okay with it because it fits their principles. Conservatives are opposed because they see it as degeneracy. Liberals support it because they hate western society. Reactionaries understand that degeneracy is a defining characteristic of civilizational decline.