Kazz: You're probably thinking of a mistrial, which can happen anytime something screws up the due judicial process; a mistrial just means you all have to start over again, at the beginning, from scratch. An appeal really is "I don't like this result".
Brentai: Sure, he does; he can't argue here that it's in violation of the United States constitution, because only the SCOTUS has the authority to find things unconstitutional under the United States constitution; however, if the case then goes to SCOTUS, he
can make that argument.
An appeal is a new trial, plain and simple; you get a different judge, a different jury, and possibly different lawyers. "You can't change your argument" would thwart one of the basic scenarios for an appeal - namely, you realized you had a bad lawyer.
At this point, the California Supreme Court is much more likely to rule in favor of gay marriage than the current US Supreme Court. That may be a few decades off.
Certainly true, but the California Supreme Court still needs to have some shred of legal grounds for making a ruling. The precedent that Brown's argument would set could have dire consequences for California's legislation; precedent means that the slippery slope is a very real thing in law.
I seem to recall hearing arguments to the effect that Prop 8 needs to go uncontested for exactly this reason - when the Supreme Court rules on something, it's pretty damn hard to get them to change that ruling, and so there's a theory that the best way to ensure high-level legality of gay marriage is to wait a few years until Obama's appointed a few new judges, and
then challenge something to bring before the court.