And, the second part of your supposition is a non-sequiter. The Constitution makes no mention of God and is actually patterned on the old Roman Republic (read: pagan) concept of a government of laws. Remember, the Founding Fathers were, for the most part, classically trained. The Constitution also owes quite a bit to 17th- and 18th-century natural philosophy. The latter holds that rights are inherent within an individual because holding that rights are bestowed by God means they are gifts, and not rights, and may be taken away by the Almighty or anyone supposedly representing the latter.
"The Constitution makes no mention of God and is actually patterned on the old Roman Republic (read: pagan) concept of a government of laws."
Excepting that a) Rights were guaranteed (and this was enforced by a document).
b) The old Roman Republic had a monarchy at times. (our country was founded as an opposition to monarchies)
c) The judicial branch was accounted for, and is to be preserved by our organization (checks and balances)
d) The idea of states holding the non-assigned (federal) powers is actually the "new" Roman Republic.
e) in fact, the Founding Fathers noted what had happend to the Roman Republic, and so built the system in a different way to avoid its same pitfalls. This country was built on what was LEARNED from the old Republic, not as a model OF the old Republic.
That being said, in the inclussion of philosophy and the subsequent measure of there being a Creator, the Founding Fathers STILL accounted for the natural Rights of Men to be of the Creator. If there is no Creator, there are no rights. This is not non-sequiter, this is truth.
If God gave us Rights: and there is no God, then there are no Rights. To deny God is to deny His blessings upon us.
"How does asking you for a definition of "free will" morph into denying a concept of God?"
It looked more like speculation to me, not an actual question. You seem to have forgotten you answered it yourself with your own suppositions. I merely used your suppositions to continue the thought:
If there is no God and we hold a naturalistic perspective, then free will may be deemed an illusion, and thus is NOT guaranteed by the Constitution. This is the exact logic that lead the USSR to establish "There shall be a seperation of Church and State" in its own Constitution. A Godless people is an oppressed people.
My understanding of "unalienable" rights is rights that cannot be sold. It was, I believe, common practice in England to enter into contracts whereby you gave up your freedom for a period of time.