Someone should start a campaign to make atheist marriages illegal in California. If that passes, then the US finally has the ammo it needs to come in and say "Hey, that constitution of yours, it's insufficient for the purposes of being a state. Fix it." (Who could say that? The DOJ? The Supreme Court?)


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But IANAL and all that.
The closest I can find to a US constitutional requirement on state constitutions is Amendment XIV, section 2, which isn't especially relevant here.
If you want US Supreme court action on gay marriage, the thing that should happen is that they should overturn DOMA as violating the full faith and credit clause. That's both what I want to happen, and my belief as to what should happen based on what the US constitution says. But it won't happen until the composition of the court changes.
If the supreme court overturned the CA constitution, wouldn't it have to overturn 40+ other state constitutions on the same ground?
I think this will happen in between 5 and 15 years.
Difficult-to-amend constitutions don't provide any real protection against the passing of provisions that violate the US constitution. I think that more than have the states now have constitutional anti-gay-marriage provisions, which I think violate the full faith and credit clause if they don't recognize all legal marriages performed in other states.
If people are too attached to the "marriage" label and hate the "civil union" label, then create a "civil marriage" label?
My agreement is that no religious figure should have any right to impose their beliefs or standards on the non-religious through laws (and possibly vice-versa).