Even the most casual observer of the debate in the United States whether to legalize same-sex marriage would be hard-pressed to ignore the significance of religion to that debate. Most obviously, a number of religious groups officially oppose or support same-sex marriage. (1) The Catholic Church, American Baptist Churches, Southern Baptist Convention, Islam, Orthodox Judaism, Mormon Church, and National Association of Evangelicals are among the groups expressly in opposition, while the United Church of Christ, Reform Judaism, and Unitarian Universalist Association of Congregations are among those expressly in support. (2) Moreover, the various groups on record in opposition or support generally have not been bashful about injecting themselves into the political fray and lobbying forcefully for the outcome that they see as right. (3)
According to a May 2011 Gallup Poll, a recent surge in public support for same-sex marriage has lifted the proportion of adults in support to slightly more than half. (4) However, if the adult population is divided into subgroups according to the importance of religion in one's life, some of those subgroups are far from evenly split between supporters and opponents of same-sex marriage. Of those surveyed in 2010 who said that religion is very important to them, only 27% favored legalizing same-sex marriage, and 70% opposed legalization. Conversely, of those surveyed who said that religion is not important to them, 71% favored legalization, and merely 27% were opposed. (5)
Many opponents of legalizing same-sex marriage have made no secret of the fact that their opposition is rooted in religion. In some instances, their emphasis is the sanctity of the favored male-female bond. For example, according to one source, the Bible "maintained that in order to become fully human, male and female must join.... The union of male and female is not merely some lovely ideal; it is the essence of the Jewish and Christian outlooks on the human experience." (6) In other instances, the argument focuses on the disfavored same-sex relationship. As one staunch critic of same-sex marriage explained, "I believe Christians must submit to the Bible's teachings, and I believe the Bible is unequivocal in its teaching that homosexual behavior is sinful. That being the case, it is impossible for me to accept same-sex marriage, which legitimizes a sinful behavior." (7)
Often, though by no means always, legislators have been more reticent about citing religion to justify their opposition to same-sex marriage. (8) Some legislators whose opposition to same-sex marriage is rooted strongly in religion may be unwilling to admit it publicly out of a political calculation that citing religion would be apt to be unpopular and cost them votes. Particularly, however, in legislative districts heavily populated by adherents to one or more of the religions on record as opposed to same-sex marriage, political calculation seems an unlikely explanation for legislators' reluctance to cite religion as central to their opposition. A more plausible explanation appears to be constitutional concerns--specifically, concerns about running afoul of the First Amendment's ban on laws "respecting an establishment of religion." (9)
In this Article, I maintain that, regardless of what lawmakers opposed to same-sex marriage may be willing to state publicly as their reasons for voting against same-sex marriage, courts should find that laws prohibiting same-sex marriage violate the Establishment Clause and uniformly should be struck down. (10) By way of general background, I begin in Part I by explaining the nonendorsement principle that the Supreme Court has recognized as central to the clause. I turn in Part II to the case law and commentary--or, more precisely, the general scarcity thereof--on the implications of the Establishment Clause for same-sex marriage prohibitions.
After explaining in Part III the basic framework for the Establishment Clause analysis that follows, I examine in Part IV the various reasons that opponents of same-sex marriage have articulated with any frequency in support of a ban. …