I have also long been saying that the arguments endorsing gay marriage must equally be applied to American polygamists (see my THREE TIERS post - http://fallofreynolds.blogspot.com/2011/08/three-tiers.html).
Recent Supreme Court decisions have prompted more commentators to acknowledge these realities. I quote in full below a brilliant article from Breitbart.com.
The road to polygamy
Proponents of gay marriage often make light of the slippery-slope argument that same-sex marriage will lead to legalized polygamy. I can see why they want to dismiss that argument, but they're being silly. Of course same-sex marriage will lead to polygamy. It is inevitable. It'll take a little while, but it's coming.Simple common sense tells us that every argument deployed in support of same-sex marriage is readily available to the polygamy activists. Who are we to tell three women and one man that they can't be in love? Who are we to deny official recognition, and government benefits, to their loving union?
This isn't just a rhetorical trick. The essence of the gay marriage argument is that the sex of the participants is absolutely irrelevant. If that's the case, then how can the number of participants be essential? Everything except the exchange of vows between legal adults in a committed relationship is being stripped from marriage. The sense that society has a deep and abiding interest in promotion the union between a man and a woman has been lost. The question is now framed purely as one of unfair exclusion: hidebound traditionalists, religious zealots, and generally mean people are trying to keep gay people from getting married, but the forces of enlightened tolerance are riding to the rescue. Read Supreme Court Justice Anthony Kennedy's majority opinion in the Defense of Marriage Act decision; he spends a great deal of time thundering that no person of good will could possibly advance a logical reason to prevent the federal government from extending benefits to same-sex couples. The polygamists will simply take him at his word, and read his decision right back to the Supreme Court, when it's their turn to make a bid for "tolerance."
I don't think the legal concept of "consenting adults" is necessarily voided by same-sex marriage, although it's under attack from other directions. For that reason, slippery-slope warnings about legalized bestiality and pedophilia are going too far. But polygamists are consenting adults. And, as a report at BuzzFeed indicates, they were very, very pleased with the Supreme Court's DOMA decison:
Noting that the court found the Defense of Marriage Act unconstitutional because the law denied marriage rights to a specific class of people, Darger said, “Our very existence has been classified as criminal… and I think the government needs to now recognize that we have a right to live free as much as anyone else.”
There's nothing illogical about what Darger is saying. The same-sex marriage movement is predicated on the notion that nuclear families are nothing special - they're just one of many alternative lifestyle arrangements, worthy of no special recognition from government or society. And the argument has indeed been framed as "denying marriage rights" to classes of people, rather than insisting upon the unique value of "traditional" marriage. (I find myself using that phrase when I write on this topic, to distinguish the traditionally understood definition of marriage from the same-sex variety, but I've heard it said that qualifying the term "marriage" in any way is conceding vital intellectual ground to those who wish to re-define it.) Why should the polygamist "class of people" be "denied" these "rights?"