Here is a typical source, from our friend John Lofton, discussing [among other things] Mormonism and the Founding:
Q: Well that’s another aspect that I hadn’t asked you about and that is that Mormonism believes or teaches basically that these founding documents of our country are pretty much sacred scripture which of course no real Christian could ever believe, correct?
A: I’m not sure exactly what you’re asking there.
Q: The founding documents, The Declaration of Independence, they pretty much consider them almost sacred scripture whereas no Christian could actually consider the founding documents to be sacred.
A: Well that’s exactly right and that’s a good point. We test all things in light of Scripture and hold fast to that which is good. So the final repository for faith and practice in a Christian world view is the word of God and everything then is tested in light of Scripture and we hold fast to that which is good.
I would also note that Mormonism is a great analogy to the religious beliefs of America's key Founders. As the American View website says: “'Bible Answer Man' Says Mormons Not Christians; Use Our Words But With Different Meanings." The same thing can be said of America's key Founders. They often used "Christian terminology" that masked heterodox sentiments. According to a strict orthodox Trinitarian view that holds Mormons not to be "Christian," even though Mormons call themselves "Christians," America's key Founders -- Washington, J. Adams, Jefferson, Madison, Franklin, G. Morris and a few others -- were not "Christians" even though they at times called themselves "Christians" and presented their heterodox theology under the auspices of "Christianity."