The state's gay-marriage bill fell victim to the lame-duck session yesterday. Eh; it's hard to imagine it not passing in the new session, when Democrats will have a supermajority. It's also hard to imagine it not passing when the arguments against it have withered into lame, ill-considered flailings. Dennis Byrne, for instance:

But, why "between two persons?" As long as we're redefining marriage, why keep this last vestige of the medieval idea of marriage? Why not three, four or as many as the blissful spouses could tolerate? If it is a denial of equal protection of the law to prohibit any two persons of the same sex to marry, then why isn't it also a denial of equal rights for three or more persons to marry? What is so magical about a couple, as opposed to a trio or a quartet? What's the big deal about monogamy?

Considering the possibility of a slippery slope when it comes to new legislation is not, in and of itself, a bad idea; it's a good way to game out the consequences of an action. So: polygamy? Why not?

First, because no one's asked for it. Consider how many gay people you know, compared to how many polygamists you know (for me the answer is lots and zero, although had I been born in another country, those numbers might be reversed). This is likely because homosexuality is a biological imperative, and polygamy is a cultural one. There's going to be a lot more natural demand for gay marriage, not so much for polygamy. 

Not that there aren't polygamists in America. And it's possible, I guess, that they could mount a challenge to marriage laws. How's that going?

Polys themselves are not visibly crusading for their civil rights. But there is one policy issue rousing concern: legal precedents concerning their ability to parent. Custody battles among poly parents are not uncommon; the most public of them was a 1999 case in which a 22-year-old Tennessee woman lost rights to parent her daughter after outing herself on an MTV documentary. Anecdotally, research shows that children can do well in poly families—as long as they're in a stable home with loving parents, says Elisabeth Sheff, a sociologist at Georgia State University, who is conducting the first large-scale study of children of poly parents, which has been ongoing for a decade. But because academia is only beginning to study the phenomenon—Sheff's study is too recent to have drawn conclusions about the children's well-being over time—there is little data to support that notion in court. Today, the nonprofit Polyamory Society posts a warning to parents on its Web site: If your PolyFamily has children, please do not put your children and family at risk by coming out to the public or by being interviewed [by] the press.

So I'm not holding my breath, and not just because there aren't that many polygamists out there. Which brings us back to Byrne:

The argument that same sex couples should have an equal right to marry is not to be taken lightly.

It appeals to Americans' ingrained sense that everyone should be treated fairly. It is memorialized in the Constitution's 14th Amendment, which guarantees to each person equality under the law.

The equality argument has been so persuasive that the Illinois Legislature may well approve same sex marriage in this lame-duck session. The elaborate public relations campaign to enshrine same-sex marriage in law couldn't have come at a more opportune time, while public attention has been focused on how Illinois is to avoid its own fiscal cliff.

There's another reason why the "elaborate public relations campaign" (sheesh) for gay marriage "appeals to Americans' ingrained sense that everyone should be treated fairly," and why polygamy doesn't. Canada's polygamist community is actually somewhat politically active, so Canadians have been hashing out the arguments for and against legalization or decriminalization of polygamy, at least a bit. From a report prepared by the Alberta Civil Liberties Research Centre (PDF):

At the international level, over the past century, there has been a movement toward the elimination of polygamy, based on concerns about the gender inequality inherent in polygamy and its harmful effects on women and children. In light of this international trend, if Canada were to decriminalize and legally recognize polygamous unions, it might be taken as a signal that Canada is unconcerned with gender equality and child welfare, since polygamy has been linked with negative effects for both women and children.

[snip]

More significant than the economic issues are the concerns about the social and psychological costs of polygamy for women and children. There is no evidence that same-sex marriage harms children, and much evidence that it benefits those same-sex partners that choose to marry. By way of contrast, as discussed in Section 2, there is a significant body of research from a number of countries about the negative effects of polygamy on children in terms of their emotional development and educational achievement. Polygamy also has significant psychological and emotional costs for women. Furthermore, the fight for same-sex marriage was based on equality arguments, and failure to recognize same-sex marriage was shown to be discrimination on the basis of sexual orientation. Recognition of polygamy would promote gender inequality.

Not all legislation has to be evaluated solely by research, but it's a good check on "common sense." Gay-marriage advocates have done their homework, presented a compelling argument, and swung approval of gay marriage from a minority to a majority in less than two decades.

Which Byrne is unwilling to recognize:

Hey, it doesn't hurt me; why should I care if siblings marry? Let them have as many genetically damaged children as they want. Their birth defects aren't my problem. [Actually, they are, which is why we regulate things that damage public health. Which there's no evidence that gay marriage does; quite the opposite.] If that sounds callous, it is because it is the fruit of the poisoned tree of radical individualism. This radical, but popular thinking says that the only things that matter are my rights. It denies that rights can be limited for a higher and wider societal good. Just where the balance is between the rights of individuals and the good of society often is difficult to determine. But it is a legitimate ground for debate, something that too many gay-marriage promoters haven't allowed.

Emphasis mine. Gay marriage advocates (not all of whom are gay!) have made the case that rights should be expanded, in the form of gay marriage, for a higher and wider societal good. The editorial in the paper Byrne is writing in makes exactly this case. Advocates would have been far less successful had they limited their case to mere rights in an abstract sense. Haven't allowed the debate? They've welcomed it, because they knew they'd win it.

Here's where Byrne finally gives up the game:

Disagree with them, and you're a homophobe.

Wait, what? I have no data suggesting that Dennis Byrne is a homophobe, but plenty suggesting he's wrong about gay marriage, and deeply misleading about its advocates.

Photograph: Jamison Wieser (CC by 2.0)