From another post I made on the subject.
Quotes are from the CASC opinion.
At the same time, as numerous decisions of this court have explained, although the initiative process may be used to propose and adopt amendments to the California Constitution, under its governing provisions that process may not be used to revise the state Constitution. Petitioners’ principal argument rests on the claim that Proposition 8 should be viewed as a constitutional revision rather than as a constitutional amendment, and that this change in the state Constitution therefore could not lawfully be adopted through the initiative process.
Now we are getting to the legal nuts and bolts. Previous case law has found the initiative process can amend but not revise the constitution. The petitioner chose to centralize their case around one simple argument:
Prop8 revises not amends the Constitution.
They drew a line in the sand.
If the courts agree that Prop8 revised the CA Constitution then the method used for Prop8 (public initiative) is invalid and it gets thrown out WITHOUT the court ever looking at the Constitutionality of its effects. This was a calculated move. Keep it very black & white and force the courts hand with a narrow scope. Sadly it didn't work out but the petitioner chose the scope. The state can only respond to questions posed by the petitioner. The petitioner never proposed that the result of Prop8 was unconstitutional. The petitioner never argued that or presented evidence to support that. The state was never allowed to present arguments against that assertion. To believe the courts could answer a question not asked is simply illogical. The courts have NEVER had that power. Judges have been removed for basing decisions on facts not entered into evidence. It is a cornerstone of our legal system. The case never was and never was going to be decided on the issue many people thought it was about.
In analyzing the constitutional challenges presently before us, we first explain that the provision added to the California Constitution by Proposition 8, when considered in light of the majority opinion in the Marriage Cases, supra, 43 Cal.4th 757 (which preceded the adoption of Proposition 8), properly must be understood as having a considerably narrower scope and more limited effect than suggested by petitioners in the cases before us. Contrary to petitioners’ assertion, Proposition 8 does not entirely repeal or abrogate the aspect of a same-sex couple’s state constitutional right of privacy and due process that was analyzed in the majority opinion in the Marriage Cases — that is, the constitutional right of same-sex couples to “choose one’s life partner and enter with that person into a committed, officially recognized, and protected family relationship that enjoys all of the constitutionally based incidents of marriage” (Marriage Cases, supra, 43 Cal.4th at p. 829). Nor does Proposition 8 fundamentally alter the meaning and substance of state constitutional equal protection principles as articulated in that opinion. Instead, the measure carves out a narrow and limited exception to these state constitutional rights, reserving the official designation of the term “marriage” for the union of opposite-sex couples as a matter of state constitutional law, but leaving undisturbed all of the other extremely significant substantive aspects of a same-sex couple’s state constitutional right to establish an officially recognized and protected family relationship and the guarantee of equal protection of the laws.
Here is the reasoning. The court found that Prop8 doesn't limit existing rights, it simply limits the name "marriage" (courts opinion not mine). If Prop8 had restricted civil unions it would have been found to be revising (not amending) the constitution. The courts found that using the term "civil union" instead of "marriage" (and limiting the term “marriage” to only opposite sex couples) does not rise to unequal protection under the law. As noted in the first quote the court isn’t looking at the benefit of such policy, or even if it is wise.
Even the dissenting judge followed this line of reasoning. He had to because that was the only question before the court. He didn't rule on the Constitutionality of effects of Prop8 he simple reached the conclusion that limiting the term "marriage" did modify the Constitution rather than amend it. It did so because in his opinion restricting the term “marriage” is unequal protection under the law. In doing so a revision instead of an amendment is not valid via the initiative process.
Essentially since CA has "civil unions" and Prop8 only restrict a name which the court found doesn't limit rights then Prop8 is a amendment not a revision since the CA constitution has no sections on the meaning of marriage.
Since Prop8 is a amendment the plaintiffs assertion that it is an unlawful revision fails and the courts decided as such.
The ONLY thing the case was about is:
Did Prop8 revise or amend the Constitution. Thats it.
If CA had no "civil unions" or if Prop8 attempted to restrict rights then likely the court (based on their opinion) would have ruled differently.