Please point us in the general direction to the Constitution (or any other official U.S document) preferably one that specifically states that citizens are exempt from any state criminal law. Precisely, the states laws that criminalize homosexual sodomy.
I have never contended that citizens are exempt from any state criminal law. I contend that the states are limited in what they can criminalize. There's a major distinction there.
The 14th Amendment says, in part:
No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States
That phrase, part of the "Due Process" clause, applied the Bill of Rights to the states. That's a good thing, or else the Bill of Rights would be meaningless. Who cares if the federal government can't ban gun ownership if states can ban gun ownership? Either it's a right retained by the people or it isn't.
Now, that hasn't stopped states from constantly pushing against the Bill of Rights (the 2nd Amendment is a good example of a right under constant threat from some states). But just because they try to do it doesn't mean they have the authority to do it - our government is replete with examples of extra-Constitutional authority seized and unchallenged.
Now, this is complicated. As I've said before, there is a great conflict between the powers reserved for states in the Tenth Amendment (which are not listed) and the rights retained by the people under the Ninth Amendment (which are not listed). We all must try to resolve this conflict in accordance with our principles. I am a lover of liberty, therefore I always default to restricting the power of the state, so I favor the personal protections of the Ninth Amendment.
Amendment XIV - Citizenship rights. Ratified 7/9/1868.
1. All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside. No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor shall any State deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.
Sexual perversion, same sex "sodomarriage", are not "privileges" or "immunities"
They're criminal acts and have been deemed as such through legislation in state laws for over two centuries. That is a fact!
There's no magic or secret phrase anywhere in any official U.S. document that will prove otherwise. That is a fact!