I just read the transcript of the oral arguments in the Prop 8 case before the Supreme Court. The arguments on the merits of the law itself were predictable and therefore, boring, so I'm not going to address them here beyond this: Equal protection clause of the 14th amendment. The initiative is out. Next!.
What I did find interesting is the issue of standing. Prop 8 being a referendum (to use the more international term for such things) came about because the elected officials didn't do what their constituencies wanted them to do, as is the case with most referenda in the U.S. (Jeez, I hope I'm pluralizing that correctly. I dropped Latin in the first week.).
Now here's the problem. It is left to the executives of the state governments to defend legal challenges to the law. Now we have a case where they decided that they don't like the law and wouldn't defend it. In other words, they wouldn't do their jobs.
Who is to defend the law when those whose job it is refuse to do so. In this case, the lower courts have recognized standing for those who put forth the initiative. but apparently this is the first time for such a thing. I think it's reasonable.
If they prevail I think that the state should have to reimburse their expenses as well, but those aren't legal arguments and I have no idea if there is any law that comes close to addressing this. If any Stanford Law constitutional scholars should see this, pass it around with your buddies and have then chime in. I'll even entertain the opinions form those who went to east coast bible colleges, Harvard, Yale, whatever.