[Interesting possibility that Prop 8 could have been lost by default. This offers a suggestion that the state once was agnostic, allowing standing, but now that that the governor opposes a stay, is this an out for the Supreme Court? The below is a response to this article.]
An independent judiciary with the power to declare unconstitutional the laws of legislatures is an important aspect of our republican system of government, a recognition of the limited power of the elected branches. As James Madison said when introducing the proposal of a Bill of Rights:
If they are incorporated into the constitution, independent tribunals of justice will consider themselves in a peculiar manner the guardians of those rights; they will be an impenetrable bulwark against every assumption of power in the legislative or executive; they will be naturally led to resist every encroachment upon rights expressly stipulated for in the constitution by the declaration of rights.
The Fourteenth Amendment in particular was ratified with this principle in mind. The rights it secured -- citizenship, privileges or immunities, equal protection and due process -- were in theory at least in part or in whole already protected by the states. Due process of law was a basis of freedom with origins as far back 1215 if not before. Each state allegedly protected it, but repeatedly, it did so in the breach, especially in respect to certain classes of people. States therefore could be the enemy.
Madison knew that too. Already, the U.S. Constitution restrained states, the federal government and its justices playing a part -- e.g., states could not use paper money for debts, a federal judge declaring that unconstitutional right out of the gate. But, Madison wanted to go further, believing:
there is more danger of those powers being abused by the State Governments than by the Government of the United States
He wanted the Bill of Rights to include protections against the states involving "equal right of conscience, freedom of the press, [and] trial by jury in criminal case." As with certain other things, he failed. But, the Fourteenth Amendment did offer more national restraints, including those upheld by federal judges, time showing the problems with just entrusting fundamental rights in most respects to popular will, even state popular will.
This is what these judges did. Rights aren't just liberal or conservative, libertarian or whatever. They can protect any number of people. The people against the ruling support judicial review in other cases, "activism" yet again too often a matter of whose ox is being gored. Their ox is better, the other not, sometimes no matter what the facts hold: as fisherman noted in response to a debate in the NYT about fish feeling pain: they simply won't accept it. This is not just something opponents of same sex marriage do either.
The facts in Arizona and California are specifically about the laws of that state invading federal law. It will be made a national issue, but the law of that state should be the immediate concern. The Prop 8 case should be about California, the facts more about that state, even if some apply to all. Focusing on that, the ruling need not be as broad as some want or fear.