Warning: long-windedness ahead!
In order to speak specifically to the California case in question from a position of less ignorance, I’m reading the full text of the decision – albeit skimming over some parts. For the benefit of those less masochistic than I, I will summarize the decision and its major arguments below. I am not a lawyer and have no training in the law besides several long-running discussions with Bricker, Dewey Cheatum Undhow, and various other more learned members of this discussion board, so by all means present any nitpicks or clarifications. The full text can be found here (nice friendly html link, pdf link to actual decision found on linked page, labelled In re Marriage Cases, (S147999))
The court holds the following:
(A) Same-sex couples have a right under the CA constitution to marry, grounded in the privacy and due process clauses. This is not a new right to same-sex marriage, but the extension of the long-recognized right to marry the consenting adult of one’s choice to a group previously forbidden access to that right.
(B) The right of same-sex couples to marry is not adequately satisfied by California’s domestic partnership legislation.
(C) Sexual orientation constitutes a suspect class for the purposes of the equal protection clause, and the justification for restricting same-sex couples from marriage offered by the state do not pass the strict scrutiny test.
The arguments:
(A) The court summarizes a vast array of cases supporting marriage (importantly, marriage to the consenting adult of one’s choice) as a fundamental right. Perez (in which California’s anti-miscegenation law was overturned) comes up more often than any other, but there are many other cases mentioned. Marriage as a fundamental right is grounded in two constitutional sources: it is one of the fundamental liberties a person many not be deprived of without due process of law (Article 1, Sec. 7(a)), and it is a part of the inalienable right to privacy (Article 1, Sec. 1). The explicit right to privacy in the CA constitution was apparently added at some point following the Griswold decision, and was explicitly enacted as enshrining a right to privacy as had been found in Griswold.
The court considers the argument that this long-established right is not the right being asked for, that the long-established right to marriage is specifically a right only to opposite-sex marriage and that recognizing a right to same-sex marriage would be finding a novel right. The court rejects this argument, saying that it is inappropriate “to define a fundamental constitutional right or interest in so narrow a fashion that the basic protections afforded by the right are withheld from a class of persons – composed of individuals sharing a personal characteristic such as a particular sexual orientation – who historically have been denied the benefit of such rights.” This is one of the key points where the dissenting opinions disagree.
The court also considers arguments presented by the Prop 22 Legal Defense Fund asserting that the right to marry is inextricably linked to procreation. The court finds this argument to be “fundamentally flawed for a number of reasons” and goes on to enumerate several of said reasons. I trust they are obvious enough I need not repeat them here.
(B) The court concludes that even though nearly all rights and obligations pursuant to marriage are granted by California’s Domestic Partner Act, by classifying gay relationships under a different name the state fails to accord the family relationships of gays “the same dignity, respect, and stature as that accorded to all other officially recognized family relationships.” They also note that Perez would have been decided the same way even if “transracial unions” had been offered by the state.
(C) The court considers three grounds for applying strict scrutiny to the equal protection claim advanced by the plaintiffs: i) that the marriage laws discriminate on the basis of sex, ii) that they discriminate on the basis of sexual orientation and that should be grounds for strict scrutiny, and iii) that they impinge on a fundamental right. The court rejects (i), citing a bunch of precedents where the use of gender classifications to pick out homosexual couples has been ruled not to be discrimination on the basis of sex.
With regards to (ii), the state apparently argued that the marriage statutes don’t discriminate against gays because gays are free to marry members of the opposite sex. This argument gets laughed out of court. To my mind if the court agrees with this argument, it has to accept the plaintiff’s argument in (i) anyways, since the statute clearly discriminates on either gender or orientation, which one depending on how you parse “discriminate on the basis of”. That it discriminates on the basis of neither is a ludicrous position. And of course, gender triggers strict scrutiny. There are some battles you shouldn’t try to win. However, two of the dissenting judges actually agree with this point, astonishingly (to me, anyways) holding that the marriage statutes don’t discriminate against same-sex couples because they aren’t singled out by name. Huh? They admit there is disparate impact, but deny that this is adequate if there is no evidence that points to intent to impose that disparate impact, and cite some precedent apparently on point. But this still makes no sense to me, because Prop 22 was very clearly passed with the intent to prevent full equality to same-sex couples. But no, these dissenting judges say the people of California were just expressing their love of tradition, or something. All I know is I want to meet their dealer, cuz he apparently has some good shit. The rest of their dissent is predictable and relatively reasonable, arguing that same-sex marriage would be a new right rather than an extension of the old one, and that orientation shouldn’t be a suspect class. This bit just blew my mind, though.
Anyways, here we get to the interesting bit – whether discrimination on the basis of sexual orientation should trigger strict scrutiny. This was an issue “of first impression” in California, and so this part of the decision may well be the most legally significant part. Even if an anti-SSM amendment is passed in fall, sexual orientation will trigger strict scrutiny in Cali from here on out (barring language in the amendment to change that, but I haven’t seen anything along those lines). The Court of Appeal in the decision under consideration had held that suspect classifications must (1) be based on an immutable trait, (2) bear no relation to a person’s ability to perform or contribute to society, and (3) be associated with a stigma of inferiority and second class citizenship. It had held that (2) and (3) were clearly met, but that sufficient evidence for (1) had not been presented, and so ruled that the rational basis test was appropriate rather than strict scrutiny. The Supreme Court disagrees with this conclusion, saying that immutability isn’t required in the case of religion, which is a suspect category in CA, and that anyways orientation is so integral a part of one’s identity that it is inappropriate to require someone to repudiate it in order to avoid discrimination.
The state argued for a fourth condition, namely that a suspect group lack the ability to use the political process to address their needs, claiming that the legislative advances made for gay rights obviates any need for strict scrutiny. To this the court says by that standard gender and race wouldn’t qualify either, and so rejects the condition (this is the point on which the dissenting opinion disagrees with the suspect classification conclusion).
Finally the state argues that if orientation is to be a suspect class it should only trigger an intermediate scrutiny, to which the court responds that they’ve never done it that way before. Suspect class triggering strict scrutiny it is.
In the strict scrutiny phase, the only state interest proferred by the defendants was “preserving the traditional definition of marriage”. Unsurprisingly, this is found to be utterly inadequate. I expect by that the Attorney General’s office knew well that if it came to strict scrutiny the jig would certainly be up, and so didn’t try to float a raftload of tenuous arguments for implausible state interests at stake.