I still think that forbiddance of gay marriage is against US constitutional law of equality of all people in front of the law.
Whats about the so called "Country of Freedom" if you use your "freedom" to limit the freedom of others? It is against what Amerca once stands for.
If you want it harsh: The rules of the catholic church are strictly against the constitutional rights in the USA.
That's, why it would be better to strictly seperate between church and law.
If you left out your catholic church beliefe against homosexual marriage, what is left against it? No valid argumentation.
Maybe homosexual pairs can't "create" their own children. But there are enough children in the USA (and other countries in the world) who have no family at all. With forbiddance of the homosexual marriage, and the denying of the rights heterosexual peopel have, you TAKE possibilities away.
Skip the discussion of "free choice of belief" because it shall not be a discussion of what people beliefe, but of facts.
And, yes, I even would say this to polygame marriage. If, say, two men are happy sharing one wife... it really can work.
I would definine marriage (in front of the law) as an engangement possible between consenting, living adults.
As stated before:
Neither buildings nor cussions are living, while neither animals nor children are consenting... or adults.