This will test the validity of Proposition 8 – the referendum proposition that succeeded in California back in November 2008, declaring that  ”only marriage between a man and a woman is valid or recognized in California.” This referendum overturned the outcome of a California court case based upon the state constitution.

It appears that the critical issue for the US Supreme Court  will be whether Proposition 8 breaches the Fourteenth Amendment to the US Constitution, whose key words for present purposes are “nor shall any State … deny to any person within its jurisdiction the equal protection of the laws.” As is well known, this provision was essentially to support the abolition of slavery (expressly covered in the Thirteenth Amendment) and to prevent African Americans from being treated by the law as second class citizens (for example with harsher punishments than whites for the same crimes, or with race-based impediments to suing, giving evidence, etc.). There has long been controversy over what discriminations other than racial ones are covered by this clause. Furthermore, it might be asked whether its purpose extends beyond such things as having a lesser protection from crimes and civil wrongs, and having lesser procedural protections when charged with crimes or sued in the courts.

The case will have immense social significance that will reverberate far beyond the United States, especially if it succeeds. Within the US, it will also have great technical legal importance in testing the limits of the Equal Protection Clause. Past cases have treated the clause creatively and expansively, so will the current Supreme Court try to scale that back? Will it be inclined to read the clause in a more narrow and technical way to avoid creating a precedent for same-sex marriage across the US?

For those who are not long-time followers of this blog, I favour the provision of access to same-sex marriage; nonetheless, there are tricky legal issues here. I don’t doubt for a moment that some respectable legal arguments can be put that the words of the Equal Protection Clause were intended to have a fairly narrow meaning. The problem for such arguments, from a strictly legal viewpoint, is that the American courts have a past history of reading the Constitution in rather expansive ways – including, as I mentioned, the Fourteenth Amendment itself. It would seem invidious if this became the case that adopted an unusually narrow approach, by US standards, to constitutional interpretation.

Importantly, the Obama administration has filed an amicus curiae brief, seeking that Proposition 8 be struck down on equal protection grounds. While the argument in the brief is supposedly restricted to circumstances in California, it is difficult to see how the case could succeed without affecting all American states that fail to provide for same-sex marriage. At the least, it would apply to all that positively forbid it, although it’s presently beyond me as to how that could be a legally relevant distinction.

It hasn’t escaped me that a provision such as Proposition 8 may be vulnerable, in addition, on First Amendment grounds relating to freedom of religion, as it is not obvious how a provision such as “only marriage between a man and a woman is valid or recognized in California” serves any plausible secular purpose. It appears to be an imposition of religious norms of conduct, although I predict that this aspect will not loom large in the hearing or the opinion of the court. If the Supreme Court is unwilling to strike down Proposition 8 on equal protection grounds, I expect that it will go to great lengths to find some kind of secular purpose, however weak or far-fetched.