One of the fundamental principles of liberalism is the equality of all citizens under the law. This means that no one is to be given special privileges or exemptions from the law, and no one is to be denied the protection and rights given by the law without good reason. Of course, some citizens, such as police officers, enjoy privileges other citizens do not, but given the purpose of their role, such privileges are justified. But when citizens who are similarly situated — that is, when all of their relevant characteristics are equal, or at least equivalent — then they must be treated equally. Equality under the law is most prominently codified in the Equal Protection Clause of the Fourteenth Amendment; it reads “(no State shall) deny to any person within its jurisdiction the equal protection of the laws.”
This Tuesday, the Supreme Court will begin hearing a case, Hollingsworth v. Perry, in which the Equal Protection Clause will play a central role. The case concerns the legality of California’s Proposition 8; passed in 2008, it amended the Californian Constitution to declare that the only legally valid and recognized marriages in the state were those between one man and one woman. Contentious ever since its origination, the proposition was first upheld by the California Supreme Court, only to be declared unconstitutional due to its violation of the Due Process and Equal Protection Clauses of the Fourteenth Amendment by the U.S. District Court for the Northern District of California; this latter ruling was upheld by the Ninth Circuit Court. Hollingsworth, defendant and leader of an anti-same-sex marriage organization, appealed to the Supreme Court.
The main argument of the plaintiffs (represented in the case by Kristin Perry, who was denied a marriage license along with her same-sex partner) will likely be based on the claim that Proposition 8, by excluding same-sex marriages from legal recognition, violates the Equal Protection Clause. The facts are very clear and are strongly on the side of striking down the proposition. First, same-sex couples constitute a real, permanent class of persons, and they are being denied recognition in a way that straight couples are not. The only difference between the two groups is sexual orientation, and it is near impossible to imagine how this difference justifies treating the two groups separately. All of the most important characteristics of persons wanting a marriage are equal: whether opposite-sex or same-sex, two non-related people desire to publicly declare and codify their commitment to support, care, and provide for one another.
That said, one purpose of Proposition 8 is to encourage (straight) couples to marry and have children, yet it provides no incentives to do so; furthermore, the legal recognition of gay marriage will in no way decrease the incentive for straight couples to marry. As explained in this amicus brief regarding the Defense of Marriage Act, this means that the exclusion of same-sex marriages from recognition fails even the least demanding standard of the Court. Furthermore, the exclusion of same-sex couples from legal marriage prevents them from enjoying several legal benefits of having a spouse. Finally, this amicus brief from the Cato Institute and the Constitutional Accountability Center presents a very strong argument that homosexual persons, and thus same-sex couples, are included in the category of persons (“all persons”) the EPC is supposed to protect.
Given all of this, it should be clear that the superior argument — both from a constitutional perspective and a more general moral perspective — is on the side of ruling Proposition 8 to be unconstitutional. It is hard to see how the Supreme Court would rule differently.