Shortly after the Supreme Court’s historic ruling in favor of the right for same-sex couples to marry, conservatives rushed to condemn the ruling by invoking the slippery slope logical fallacy that permitting gay couples to marry opens the door to legalizing polygamy too. Conservative commentator Bill Kristol tweeted “Polygamy here we come”. Fox News host Martha MacCallum queried:
So suppose three people say, we want to be a marriage; we’re three people, and we love each other, and we want to be a marriage. What’s to prevent that, under this?
Even Supreme Court Chief Justice John Roberts employed the “slippery slope to polygamy” argument in his dissent, arguing:
It is striking how much of the majority’s reasoning would apply with equal force to the claim of a fundamental right to plural marriage. If “[t]here is dignity in the bond between two men or two women who seek to marry and in their autonomy to make such profound choices,” why would there be any less dignity in the bond between three people who, in exercising their autonomy, seek to make the profound choice to marry?
Sadly the Chief Justice of the Supreme Court and the conservative commentators who echo his argument seem to lack understanding that slippery slope arguments are logical fallacies. There is no relationship between same-sex marriage and polygamy. In fact, historically, polygamy has been almost exclusively practiced in conservative, male-dominated patriarchal cultures that are the antithesis of the progressive and liberating redefinition of marriage being promoted by LGBTQ Americans and their straight allies.
Societies and sub-cultural groups that have practiced plural marriages have been hetero-normative rather than gay friendly. While conservatives enjoy making absurd slippery slope arguments in their feeble attempts to discredit same-sex couples, their arguments are wrapped in emotion rather than logic.
To illustrate the flawed logic of the conservative’s arguments, the slippery slope fallacy can be applied with equal silliness to straight marriages. If a man is permitted to have one wife what is to stop him from having two or even three wives? While that argument may seem patently silly, it is parallel to the argument conservatives are making against same-sex marriages. Well, almost parallel. The truth is a man with one wife is one wife closer to having multiple wives than a man who has no wives and a husband is to having multiple wives.
If conservatives want to argue that gay marriage should not be legal, they have every right to make their case. However, if the best they can come up with is the faulty argument that allowing gay marriage opens the door to polygamy then they might as well keep their mouths shut. If that is the only objection they can muster, it fails basic logic and they have no case.