Slipping Toward Polygamy

Matt Yglesias argues that conservative slippery-slope predictions actually do tend to come true, but by the time they do the slippage, once thought to be self-evidently bad, is considered a good thing. So racial equality did lead to interracial marriage, but most people now approve of interracial marriage. Based on this track record, Yglesias predicts that same-sex marriage will indeed pave the way for polygamy.

Some of his commenters don't buy it, arguing (correctly) that there's no reason that accepting same-sex marriage necessarily entails accepting polygamy. But slippery slopes aren't about logical relationships, they're about causal relationships. Social and cultural change are not processes characterized by a great deal of logic.

In this case, I think that the conservative slippery slope is a self-fulfilling prophecy. By making the slippery slope argument, conservatives have planted the idea in people's heads that gay marriage leads to polygamy. If conservatives fail to stop same-sex marriage, then, people will start to ask themselves "why not polygamy too?" Enough people will accept this connection and decide to give it a try without the support of legal recognition. This will swell the ranks, and increase the visibility, of the polyamorous community. This, in turn, will begin to alter our assumptions about what polyamory is like -- the first images to come to mind will be loving and egalitarian relationships, rather than the Mormon patriarch with his underage harem (a process not unlike the image-altering effects of the San Fransisco marriages last year). Eventually, attempts to get polyamory legally recognized will arise (assuming that the other conservative prediction, that same-sex marriage will destroy the institution of marriage, has not come true yet).

(As it happens, I'm way ahead of Yglesias' historical curve on this one, as I already think that polygamy is an acceptable choice.)