Note that the question here is not whether state officials are required to defend the law in the original hearing, but whether officials are permitted to accept the ruling of the lower court when that ruling rejects a measure. If officials are not permitted to accept such a ruling by a lower court as to the constitutionality of a measure, then one has to ask why these matters shouldn't as a rule go first to the Supreme Court.

Given the present court system, requiring state officials to exhaust their appeals in defense of a measure would creäte an asymmetry in favor of whatever measure had passed; laws would always have to be accepted as in accord with the constitution unless challengers had the resources to fight all the way to the Supreme Court. Beyond that, the residual function of the lower courts would be to allow appeals courts and the Supreme Court to moderate their work-loads by refusing to hear an appeal.

The question of whether supporters of Proposition 8 have standing to appeal the lower court ruling should turn not upon whether this were the only way to ensure that a law is fully defended, nor upon whether it is the only way that what may plausibly be their rights should be defended, but upon whether indeed it is at all plausible that their rights are at stake, regardless of whether state officials are doing anything to protect those rights. If a party were not given standing to defend its rights, on the grounds that state officials were providing such a defense, then state officials could erode those rights by providing a weak defense.