Prior to the astonishing recent victory of same-sex marriage, its advocates treated the polygamy question with contempt.  “If same-sex marriage is accepted,” a supporter would be asked, “what’s to stop us from allowing polygamous marriage next?”

Undoubtedly, some who asked this question were genuinely interested in probing the internal logic of same-sex marriage acceptance.  They wondered: If we approve this expansion, would that pave the way for other non-traditional marriage arrangements to also become legal?

In the hands of others, the polygamy question was not so much a genuine inquiry as a rhetorical strategy.  It’s not hard to see why it would be used this way, either.  In a Gallup poll taken a little over a year ago, only 14% of Americans said they approve of polygamy, making it less popular than suicide (19%).  (Consolation prize for polygamy: it safely triumphed over adultery, which received a paltry 7% approval.)  Compare this to the remarkable ascendancy of same-sex marriage, a position that less than fifteen years ago received 35% approval and now enjoys nearly twice that.  Witnessing this transfiguration, opponents of same-sex marriage attempted to conceptually link same-sex marriage and polygamy in hopes that the latter’s unpopularity would erase some of the former’s.  This had an effect on supporters, who were bothered by the politically destabilizing effect that an association with a far less popular measure could have on the prospects for same-sex marriage acceptance.

Now, in a post-Obergefell America, the polygamy question reappears – not as a polemical strategy, but as a legitimate inquiry.

Indeed, why not polygamy? Is there any reason not to further expand marriage to accommodate group arrangements?  The answer is no – not based on the reasoning that has just approved same-sex marriage.

One problem is that past forms of polygamy – as well as current ones – have led to socially undesirable consequences for its most vulnerable participants: women and children.  Indeed, according to Shoshana Grossbard, polygamy is “anathema to women’s economic, social and emotional well-being,” and according to Libby Copeland, it “discourages parental investment.”

What are we to make of these assessments?

One thing we can note is that history is a reliable guide here only to the extent that the conditions it specifies are more or less continuous with our own.  At one point, the dinosaurs thrived; not so much anymore, summer blockbusters notwithstanding.  Here’s the point: why should we think that how polygamy was practiced back then is how it would be practiced today?  The same goes for contemporary examples.  There are many versions of polygamy, both from history and from our modern world, that run afoul of our commitment to liberalism.  The only way for this argument to succeed is for it to be shown that these illiberal or harmful features are inherent or intrinsic to polygamy.  If the features are inessential, however, then they can be ameliorated through carefully constructed legislation.

On that note, the philosopher Martha Nussbaum asks:

What about...a practice of plural contractual marriages, by mutual consent, among adult, informed parties, all of whom have equal legal rights to contract such plural marriages? What interest might the state have that would justify refusing recognition of such marriages?

Nussbaum’s suggestion is that group marriage, fashioned along liberal and egalitarian lines, makes sense for Americans to accept.  She acknowledges that “as traditionally practiced, polygamy is one-sided” because “[m]en have [had] rights that women do not.”  Nussbaum is at pains to emphasize that by accepting polygamy, the state does not thereby commit to accepting all variations.

Not so fast, says Jonathan Rauch, in a recent piece for Politico.  Rauch, of course, has been a top voice in the push for same-sex marriage acceptance.  He’s not as sanguine as Nussbaum is about the prospects of eliminating these inegalitarian elements from polygamy.

Rauch has two main critiques, one charging polygamy with inegalitarianism, the other charging it with producing socially harmful consequences.  His contention is that if polygamy is accepted, "low-status” men will have inferior options in what is now a diminished marriage market.  This alleges an inequality of marital opportunity.  His second critique is that this will drive these “low-status” men to crime and violence, thus generating ill social effects.

Rauch supports his second critique by citing the rampant displacement of marriageable men in a northern Arizona Mormon sect.  But this example has little value as a cautionary tale, since the description it offers of the sect’s treatment of its men is not indicative of wider cultural norms.  The sect itself is highly irregular relative to the rest of America, its marriage norms very different relative to how the marriage market operates in society more broadly.  The form of polygamy that led to this result would be disallowed (see Nussbaum, above) or the features that gave rise to the displacement of these men would be eliminated through a more efficient marriage market, which we should expect to follow when polygamy is no longer the exclusive province of fundamentalist communities. 

But even more curious than the above is Rauch’s support for his first critique.  He focuses exclusively on the inegalitarian outcomes for men and not the equality-enhancing outcomes for women.  Notice that Rauch cites the plight of the “low-status” men.  What about the gains that women make from having their marriage market expanded?  Previously, when a “high-status” man was taken off the market, this represented a loss for every woman in the community other than the one the man married.  Not so anymore.  The market has expanded for women, and not just quantitatively, but qualitatively.  There are greater opportunities to marry a “high-status” man under this system, an outcome Rauch ignores.

In a society in which individual autonomy is the chief good, the state’s preoccupation becomes protecting each person’s capacity for self-definition.  When two or more persons are involved, consent becomes all-important, which is why Fredrik DeBoer made it the lynchpin of his argument for polygamy legalization in a recent article for Politico.

Not all definitions are equally enlightened, however.  When the government dislikes a societal feature, it may attempt to suppress it, justifying its actions by implicitly invoking a harm principle.  Witness the lip service paid to the right of bodily autonomy: an abortion is fine, but doing drugs is not.  How can this be?

The problem is that it’s not clear that doing drugs, or eating fatty foods for that matter, represents true self-definition.  The state sees these behaviors as obstructing self-actualization, not promoting it.  So in these cases, it sometimes tries invoking the harm principle in its attempts to curb them.  Harm considerations become more important than consent or autonomy when the state sees a given action as inimical to flourishing.  Usually, though, the harm consideration is trumped by an action’s autonomy-enhancing properties.

There is no doubt that if same-sex marriage passes the test, so does polygamy.  This is not my position; it’s the position America has already taken.  Arguments saying otherwise are failing to follow the logic.  In the end, logic wins.

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