It's not a fact, Buck. There is no theistic idea of rights. And "God" is not mentioned in the founding documents - just a creator. My creator was the laws of nature acting most immediately through my parents.The American democracy is not founded on secular humanism. It is founded on the theistic idea that human rights derive from creation by God. This is no proof that the proposition is true, but the fact remains.
Civil rights and political freedoms were consistent with Enlightenment ideals, not any holy book or church. Jefferson's lip service in the Declaration to a creator endowing those rights and was irrelevant except possibly to assuage theists concerned about the legitimacy of rights not granted by a king.
Freedom and democracy have nothing to do with Christian dogma. The Christian god doesn't share power, take surveys, or hold elections. He's authoritarian, and his agents on earth are divinely chosen monarchs.
The following is from the Affirmations of Humanism. Can you present us with anything analogous from this "God" or its bible?
"We believe in an open and pluralistic society and that democracy is the best guarantee of protecting human rights from authoritarian elites and repressive majorities."
Here's what the bible says about democracy:
"Remind them to be submissive to rulers and authorities, to be obedient" - Titus 3:1
"Let every person be subject to the governing authorities. For there is no authority except from God" - Romans 13:1
Is it helpful for you to keep making that claim knowing that it will likely elicit this response? Is that a net gain for your position?