As a professional advocate, supporter of the legalization of same sex marriage, and a religious man who regards the Bible as my primary source of moral direction, I find this strategy appallingly bad. It falls into the category I generally label: "is this about feeling good or about being effective." Being effective usually involves a framing that allows opponents (especially at the margin) to incorporate and adopt your view as easily as possible. In this case, the objective would be to demonstrate that the vision of marriage in the Bible is not antithetical to marriage as between same sex couples, or that one's personal faith in the Bible should of be the determinant for society as a whole. Indeed, surveys of people of faith ages 30 and below find that a healthy plurality believe that even if they personally think marriage is between a man and a woman, they do not support limiting the secular/legal definition of marriage to exclude same-sex couples.
The attack strategy, by contrast, reenforces to those at the margin that opponents of gay marriage are correct when they site gay marriage as only the latest attempt to undermine religious culture and faith in the Bible as a whole. It makes it harder for them to amend their worldview to include same-sex marriage. It is also alienating generally to those with positive feelings toward the Bible, even among supporters of same sex marriage, because it creates a conflict. Either you believe in the Bible, and its highly negative view of marriage, or you side with us. This is acceptable in team sports, but lousy advocacy policy.
It may be that advocates of this approach may be seeking to force opponents at the margin to confront the fact that a literal interpretation of the Bible would conflict with their overall worldview, and that consistency therefore requires to abandon literalism in favor of a more general interpretation. Lets call this the "God hates shrimp" approach. Unfortunately, if this is the intent, it is being profoundly poorly executed.
I had hoped to dig into the concept of marriage as expressed in the Jewish interpretation of the Bible and Jewish tradition at some considerable length, but this proved too much. Hopefully, I will address this larger concept at some future date. Instead, allow me to make just a few observations from my perspective.
The Difference Between Narrative and Halacha
We begin with the interesting distinction that, for traditional Judaism, the primary purpose of the Bible is as a legal code rather than as an historic narrative or a cosmology. Indeed, a popular question in the first age of exegesis is "why do we have Genesis at all?" It is therefore important, when trying to derive the idea of a biblical concept of marriage, to differentiate between narrative and the law code ("halacha").
In this regard, it is noteworthy that the language of sex is entirely different in the narrative portions than in the legal code. The Bible uses three words to describe sexual relations as part of the Old Testament narrative. "Vayaidah," which translates to "and he knew," as in "and Adam knew Eve his wife, and she conceived." (Gen. 4:1) "And Elkannah knew Hannah his wife, and she conceived." (Samuel 1:19) Contrary to popular belief that "to know" is the default Biblical euphemism for sex, "vayaidah" is used very rarely to mean sexual relations and is used in situations that imply emotional as well as physical intimacy. The second word to describe sexual relations is "vayavoh," literally "and he went to." e.g., "and he [Abram] went to Tamar and she conceived." Gen 16:3 This implies consensual sex but no emotional intimacy. The third word used is "vayikach" "and he took." This word is used in the context of rape, such as in the rape of Dinah.
All of these words to describe sexual relations in the narrative focus to some degree on the relationship between the individuals (they are also all from the male perspective, at least in that they describe the male as the actor). By contrast, the words in the legal code (specifically the "Holiness Code" of Lev.) are action oriented and utterly indifferent to the emotional nature of the relationship. While this does include "vayikach" in the context of consensual relationships, the common descriptors are "yishcav" (trans "shall lie with") or gilah ervat X (uncover the nakedness of X).
The difference in language highlight a critical difference in the aspirational notion of marriage as a relationship v. the recognition in the legal code of marriage and sexual relationship generally as being legal and social constructs critical to societal purposes as well an expression of an individual relationship. Interpretations of the legal code separate from the complex legal and social matrix as if they were comparable to narrative is neither faithful to the text nor to the traditional interpretation thereof.
Complexity of the Legal Code
In understanding the legal code, it important to appreciate its complexity and traditional interpretation. For one thing, the written legal code was not intended to be interpreted in the absence of the oral code and principles of legal interpretation. Further, many of the commandments are traditionally considered either concessions to human weakness (such as the law of the female captive) or an attempt to mitigate what would otherwise be considered irreparable harm in an economic and social context (the betrothal/sale of the pre-teen daughter, leverite marriage, rape). While we may argue over whether these represent a desirable system of laws or conflict with modern understanding of morality (and, if so, how we reconcile the inherent contradiction with our conception of God and the role of halacha), they cannot fairly be said to provide a model of a *healthy* or *ideal* marriage.
Accordingly, the argument that the Bible is a crappy guide to marriage because it permits certain outcomes in particular cases is not really a very logical or persuasive argument. The Bible does not hold up the Leverite marriage as an ideal marriage. Rather, it permits it as an exception to the general rule prohibiting marrying an in-law for economic and social reasons that are no longer relevant. But this tells us nothing of the ideal of marriage or its basic role in society. One may as well argue that the existence of spousal immunity in some states, which permits a spouse to refuse to testify against an abusive husband, means that all secular marriage is crappy.
Marriage and Sexual Conduct As Part of Broader Holiness Code/Nation Building
Finally, the Biblical concept of marriage and sex is not individual-centric. This is explicit in the "Holiness Code" prohibiting various sexual relationships (including, at a minimum, anal sex between two men) is explicitly an exercise in nation building and national identification. It fits within a broader pattern in which basic human behavior (e.g., eating, defecating) is viewed as subject to constraint with the goal of transforming the observant into "priest and a nation of priests." Thus, prohibited sexual relations are prohibited in part to distinguish the Children of Israel from the inhabitants of Canaan.
Similarly, the case of the Daughters of S'laphchod is noteworthy because it represents resolution of a conflict between the rights of individuals and the rights of the Tribe. As explained in Numbers, the Daughters of S'laphchod approach Moses at the time of the division of the land among the tribes and families. Their father has no male heirs, wherefore should they lose their inheritance? God declares the Daughters of S'laphchod are correct and that they shall inherit their father's property. Later, the elders of their tribe approach Moses about an unintended consequence. The Tribes are each given their own territory. But if the Daughters of S'laphchod marry members of another Tribe, then the land will pass to the other Tribe (since tribal membership follows the father, even though it is the status of the mother that determines whether a child is born Jewish). Moses again consults God and God agrees that the integrity of the Tribe must be protected, so that if a woman inherits her family's land, while she may marry a man of her own choosing, it must be from her own Tribe.
My purpose is not to debate how we should regard this generally, but rather to demonstrate an illustrative principle of Biblical marriage. While personally autonomy is significant, it is only one element in a complex system defining relationship to God, relationship to the Nation, and the individual relationship at the center. The effort to denigrate this complex system by tossing out a few isolated sentences is akin to the tactic of conservatives of taking a few regulations out of context and declaring "see how awful and irrational is the regulatory state!"
To conclude, it is poor tactics to grab a few random sentences from the Bible as evidence that the entire "Biblical" concept of marriage is a corrupt anathema best discarded by any rational modern thinker. But it is also intellectually dishonest. It is the Progressive equivalent of "death panels," pointing to "pages of regulations," and the other rhetorical tricks used to support an unthinking deregulatory agenda. Its sole redeeming feature appears to be that it allows its advocates to feel smugly superior about themselves. I am well aware that "good causes attract bad advocates" or, to paraphrase Alton Brown "even good advocates have bad arguments." But it is invariably disappointing to see those with whom I agree, and generally respect, adopt the same intellectually bankrupt arguments they have ridiculed in others.