The CA Supreme Court has two avenues they can follow that justify their insertion here.
First, the referendum process can amend the state constitution, but cannot revise it. Revisions must go through the standard process, originating in the legislature. There is no actual guidance on the difference between amending and revising. The courts have ruled in the past that a revision is a larger rewriting, affecting multiple areas of the Constitution. By that criteria, prop 8 appears to be OK, but since the amendment/revision criteria is pretty much at the Court’s discretion, they do have room to insert themselves.
The other way they can insert themselves is to claim that prop 8 violates the federal constitution. Given that DOMA is current law, this seems unlikely. Yes, they’re a state court, but I understand they are allowed to rule on the federal issues, or maybe it was passing it to a federal court - a friend went over these with me, I might be messing up this second point.
Hope that answers your question,
Drew Garrett
Thank you both very much.