In re-reading and pondering the decision, I keep coming back to this:
In contrast to earlier times, our state now recognizes that an individual’s capacity to establish a loving and long-term committed relationship with another person and responsibly to care for and raise children does not depend upon the individual’s sexual orientation, and, more generally, that an individual’s sexual orientation like a person’s race or gender does not constitute a legitimate basis upon which to deny or withhold legal rights.


Once you alter that basic understanding, then re-fitting the law to account for it may, at first blush, look liberal or activist, but in fact, it's just removing what now appears a massive anachronism and anomaly. Yes: this means that the court is dong something the first Californians would have regarded as outrageous. But that goes for so many other issues as well, especially race and gender, where our core definitions have shifted with time and knowledge.
Is this shift an ideological one? I don't believe so. It's an empirical one, based on increased knowledge of who gay people are. Once you absorb this knowledge, this evidence, this truth, legislative schemes which arbitrarily separate gay people from straight people - and put gay relationships in a separate and unequal box - seem grossly unfair, and certainly a violation of the equality promised in various state constitutions. I think that's what has really happened in the two decades I've been arguing about this. We have altered our view of homosexuality. And the alteration is not one of degree but of kind. And so the law must adapt. Maybe it has happened too quickly for easy cultural digestion. But it is inevitable if we are not now to replace knowledge with fear, and inclusion with, yes, prejudice.
(Shameless plug: My first book, Virtually Normal, the first extended case for equal marriage rights, can be bought here. My recently updated anthology on all the various aspects of the marriage equality debate can be bought here. My 2000 TNR essay on why civil unions are not enough can be read here.)