Federal District Court Judge Vaughn Walker's overturning of Proposition 8 has reignited one of the fiercer sub-debates on same-sex marriage: the "slippery slope" issue. The main question, as Peter Ferrara recently wrote for Fox News, is this: "If there is no rational basis for a distinction between heterosexual marriage and homosexual marriage, is there a rational basis for a distinction between bigamy or polygamy and monogamy?"

That depends whom you ask. Same-sex marriage advocates generally denounce the question as a right-wing scare tactic: of course there is a difference between same-sex marriage and polygamy, they respond. Yet among opponents, debate continues. Here are the recent responses Judge Walker's decision, as well as heavyweight opinions on the debate in the past few years.

On Walker's Ruling

  • Applying Walker's Decision to Polygamy Joe Carter at Catholic magazine First Things attempts to go point by point through Walker's rationale, figuring out whether it could be used to support polygamy. The ideas, for example, that Proposition 8 stigmatizes gays and lesbians, increases costs for these couples, and "singles [them] out ... legitimat[ing] their unequal treatment" could all apply to polygamists as well. Furthermore, argues Carter, the issue with "tradition" isn't an obstacle where polygamy is concerned:
Unlike gay marriage, polygamy has been widely practiced throughout history. There are few civilizations, religions, or cultures where polygamy has not taken root. In fact, almost ever religion has, at some point in their development, accepted the legitimacy of polygamy ... This leaves proponents of same-sex marriage with two choices. They either have to accept that polygamy is just as legitimate as gay marriage or they must admit that there is no inherent "right" to expand the definition of marriage.
  • Problems in This New Definition of Marriage Ken Klukowski and Ken Blackwell, special counsel Family Research Council and visiting professor with Liberty University School of Law, respectively, argue at The Huffington Post that the district court's definition of marriage-- "Marriage requires two parties to give their free consent to form a relationship, which then forms the foundation of a household"--is fraught with issues, not least of them being that no particular justification is offered for the word "two." Also: can the two parties be underage, or close relatives?
  • Equal Protection? Walker's "interpretation," writes Logan Penza at The Moderate Voice, "appears to be that there exists a fundamental right to marriage that cannot be selectively limited by statutes that state who may marry whom. But to embrace that interpretation of the Equal Protection Clause would require, among other things, overturning anti-polygamy laws as well." Penza does argue, though, that the idea that legalizing child-marriage or bestiality would soon follow is a bit much.
  • Oh, Calm Down "The question of polygamy is completely separate from that of gay marriage," dissents Daniel McCarthy at The American Conservative:
One may follow on the tails of the other, but there's no reason, even by the state's peculiar logic, why that must be so. (Certainly plenty of societies have had polygamy without gay marriage.) Conservatives are right to see large implications behind the liberal view of marriage, but they have failed to confront the fact that the liberal view of marriage was already triumphant long before gay marriage appeared on the horizon.
Previous Takes on the Debate
  • The Economic Distinction Between Same-Sex Marriage and Polygamy  Back in 2006, law professor Ann Althouse wrote a forceful response to those afraid of polygamy legalization. "Legal marriage isn't just about love," she wrote: "it's an economic arrangement," and even those same-sex marriage proponents who doubt that should remember: "The law doesn't assess how much two people love each other. Two persons of opposite sexes can marry for all sorts of reasons." State-sanctioned marriage "affects taxes and employee benefits--huge amounts of money," and, as a result, there's a big difference in terms of "fairness" between same-sex marriage and polygamy: "A polygamous marriage ... puts a group of persons in a position to claim more economic benefits than the traditional heterosexual couple." Law professor Eugene Volokh, though, notes by way of response that a polygamous group could decide they're not "asking for benefits that would extend to all the spouses in the family," but just "what two-member families get"--the "symbolic value" and perhaps the economic benefits for two of the members.
  • The Logistical Distinction "The key difference," wrote David Link, an attorney who has worked with the California legislature, in a lengthy 2006 email posted on The Volokh Conspiracy, "can be found by asking a fairly simple question ... : in a polygamous marriage, who is married to whom?"
Same-sex marriages have the same dyadic structure that all heterosexual marriages now have. Each partner is married to the other, and only to the other. Their rights and obligations to one another, to any children they may have, and to any third parties who might have some interest in the relationship, such as banks, creditors, parties to contracts, etc., are usually quite clear.

That's not true with polygamy ... As a matter of public policy, are [the separate wives] legally married to one another the way a husband and wife are under current marriage law? Stay with that question. If the answer is "yes," then if the husband died, would the wives continue to be married to each other? Why or why not? ... Could some or all of the wives divorce the husband, but continue to be married to one another? Could they divorce one another? ... If anyone wants to argue in favor of polygamy ... they will have a lot more questions to answer than advocates for same-sex marriage do.