It is. But we know that the left has an agenda that has nothing to do with truth and reality. God stands in the way of their plans. So does anyone who believes in Him. Including the Founders.
The "quote" from Jefferson was indeed hacked. It is from a letter to Thomas Cooper in 1814. In the letter Jefferson talks about Common Law and Christianity. It is very long and atheists picked ONE line out of many. Normal behaviour to pluck something out of context. They are discussing the history of English law.
If, therefore, from the settlement of the Saxons to the introduction of Christianity among them, that system of religion could not be a part of the common law, because they were not yet Christians, and if, having their laws from that period to the close of the common law, we are all able to find among them no such act of adoption, we may safely affirm (though contradicted by all the judges and writers on earth) that Christianity neither is, nor ever was a part of the common law.