As I was reading the opinion in the CA same-sex marriage case, I started taking notes for my own use, and it occurred to me that they might be useful to others as a summary, even though I am not (of course) a lawyer. So I'm presenting my notes here.
That said, it turns out that the first twelve pages of the opinion form what look to me like a complete summary of the more detailed discussion in the full opinion (which I haven't read yet), and those first twelve pages are readable and clear and worth reading. So if you have ten or twenty minutes to spare, go read the beginning of the opinion.
But I've written my mini-summary, so I'll post it anyway. In the following, "we" means the Supremes; my own editorial comments appear in [square brackets]. All bits in quotation marks are direct quotes from this opinion, not quotes from earlier cases.
pp. 1-4: Most other states' Supreme Courts that have had same-sex marriage cases have been resolving issues different from the CA issue. In most other states, the question has been whether same-sex couples can get the same rights as they'd get in a marriage. In CA, though, domestic partnership is already very similar to marriage, so the question here is whether it's unconstitutional to call the same-sex version something other than marriage. [My impression is that there are a few remaining important rights that aren't afforded to D.P.s, but I'm not certain of that, and in this opinion the Court consistently takes it as read that D.P.s are effectively marriage by a different name.]
pp. 4-5: We're not looking at the policy question of what should be legal; we're only looking at "whether the difference in the official names of the relationships violates the California Constitution." [emphasis in original]
pp. 5-6: Past cases establish the "right to marry" as a fundamental constitutional right in CA. Perez v. Sharp (1948), by stopping the ban on interracial marriage, implicitly established "that history alone is not invariably an appropriate guide for determining the meaning and scope" of that right.
p. 7: Past cases establish that the right "of two adults who share a loving relationship to join together to establish an officially recognized family [...] constitutes a vitally important attribute of the fundamental interest in liberty and personal autonomy" secured by the California Constitution.
p. 7: Given how important the "constitutional right to form a family relationship" is, we interpret the constitution as "guarantee[ing] this basic civil right to all Californians, whether gay or heterosexual, and to same-sex couples as well as to opposite-sex couples."
p. 7 footnote: We'll use "gay" to refer to both lesbians and gay men, and "gay couple" to refer to same-sex couples. [Nice of them to make this explicit, but fooey on them for ignoring bisexuals. On the other hand, in fact they later do use the term "same-sex marriage" extensively.]
pp. 7-8: The Attorney General, arguing in defense of the existing law, says that even though the rights are the same, the term used doesn't have to be. By the way, we don't have to decide here whether it would be okay to use a term other than marriage for all civil marriages; we just have to decide whether it's okay to use two different terms with two different groups.
pp. 9-10: Even though the rights afforded by marriage and D.P. are basically the same, "current California statutes nonetheless must be viewed as potentially impinging upon a same-sex couple’s constitutional right to marry under the California Constitution." Also, the different names raise equal-protection concerns. Furthermore, the "strict scrutiny" standard for equal-protection concerns applies here, because we conclude that sexual orientation is "a constitutionally suspect basis upon which to impose differential treatment." [In other words, sexual orientation is specially protected (wrt discrimination) in the same way that gender and race and religion are. Cool!!]
pp. 9-10 footnote: We'll use the term "plaintiffs" to refer collectively to the people challenging the statute. When we refer to the defenders of the statutes collectively, we'll call them "defendants."
pp. 10-11: Under the "strict scrutiny" standard, the state has to establish that it has a compelling interest in the different treatment, and that the different treatment is necessary to serve that interest. We conclude that "the interest in retaining the traditional and well-established definition of marriage [...] cannot properly be viewed as a compelling state interest for purposes of the equal protection clause, or as necessary to serve such an interest." [emphasis in original]
pp. 11-12: We reach that conclusion for various reasons. First, "permitting same-sex couples access to the designation of marriage will not deprive opposite-sex couples of any rights." Second, there's real harm to same-sex couples "because denying such couples access to the familiar and highly favored designation of marriage is likely to cast doubt on whether the official family relationship of same-sex couples enjoys dignity equal to that of opposite-sex couples." Third, gays have been disparaged in the past, which makes it more likely that the exclusion will be seen as an official statement of lesser status. Finally, the separate terms may perpetuate the idea that gays are second-class citizens.
p. 12: "Accordingly, we conclude that to the extent the current California statutory provisions limit marriage to opposite-sex couples, these statutes are unconstitutional."
Okay, I gotta go to work. I'm hoping to read the rest of the opinion later today, but I doubt I'll be taking notes at this level of detail.