Opponents are also seeking to have the amendment nullified, arguing that it alters the state's constitution -- meaning the state Supreme Court's May ruling -- and therefore, according to state law, is a revision that requires a constitutional convention.
Um, they argue that the amendment 'alters the constitution'. That's not an argument, that's the definition of an amendment.
The CA SC ruling is an interpretation of the CA constitution, saying that the constitution requires equal protection for the rights of individuals to marry, regardless of their sex. It overturned the referendum (why do they call these things 'ballot initiatives' these days; that's just confusing) DOMA law that passed in CA in 2004. SO....
It's obvious that the entire reason for being of prop 8 is to change the meaning of the constitution so that it WILL allow for discrimination in access to marriage based on sex.
Now it seems to be the case that somewhere in the CA constitution - I should go read it, but none of the articles that talk about this stuff give any cites or links, so I'm being stubborn - it distinguishes between amendments that require a convention and those that don't. At the moment, that sounds like a STUPID distinction. If you are altering the meaning of the highest law of the (state) land, then you are altering its meaning. I don't see how you can choose between minor alterations and radical ones. And who would decide, anyway, since we are already dealing with the most radical and fundamental political act there is - changing the constitution.