I'm curious. Does your libertarian attitude extend to muslim genital mutiliation, of minors?
They do that supposedly for religious reasons. Keep the state out of their religion?
Likewise child-wives, polygamy etc? For religion's sake?
I don't get the connection. Marriage is a contract entered into between consenting, competent adults. Child abuse (whether justified by religion or otherwise) has nothing to do with one's stand on marriage equality, or the equal protection clause of the Constitution.
While I have practical reasons for favoring marriage equality (it encourages monogamy and responsible behavior, and discourages marriage alternatives like domestic partnerships (see my post above)), the LEGAL justification is the Constitution's equal protection clause. It's not a matter of the feds usurping the states' role in legislating the marriage contract, it's the fact that valuable benefits and protections are accorded by the states to such contracts. It was the arbitrary denial of those benefits and protections that triggered the equal protection violation.
But that's neither here nor there - you want to talk about religious liberty and my "libertarian" attitude. I recognize the Constitution protects religious liberty, but as with any other right the issues emerge when that right conflicts with the rights and justifiable expectations other citizens. Folks have the right to sit at a public lunch counter, or shop at a public store, and not be arbitrarily denied service. The owner of the lunch counter or store in turn has the right to sell only the goods and services he wants. A kosher deli can't be forced, for example, to sell pork. But if you choose to sell pork, shouldn't you be obliged to sell to all your customers who see the sign on your door?
I understand the issues at stake in the Christian baker cases, and they're not easy to resolve. Genital mutilation isn't quite that difficult IMO - religious liberty doesn't extend so far as to allow a parent to abuse his/her own child. The technical legal issue is whether a claim of "religion" can trump a law of "general application". The law generally prohibits child abuse - should a justification of religion provide an exception? The law generally requires a public lunch counter to not discriminate - but is discrimination okay if justified by "religion"? And key to resolving such conflicts is determining just who the victim is. Does the child need protection from its abusive parent? Is the customer of the bake shop a victim, or is it the baker whose conscience is offended by the customer's request to purchase what he's advertised for sale?