I want to unpack this phrase Judeo-Christian heritage, which is both empty and wrong.
Sure, we were deeply influenced by some Biblical principles. The idea that we had immutable rights to liberty -- that couldn't be taken away by a King or a parliament -- came from a religious conception of man as created in God's image. Those rights were, therefore, "endowed by our Creator."
But the construction of our government was also influenced by Rome, and yet we don't talk about being influenced by the Zeusian-Ceasarian heritage. Locke and Montesquieu influence the Founders views greatly yet we don't applaud our Anglo-French Heritage. Obviously some folks focus on the Christian influences in the hope that it can ward off either pure religious pluralism, secularism or excessive separation of church and state.
Nonetheless, let's go further and posit that of the many influences on our nation, religion was one of the most important.
But "Judeo-Christian"? Nuh uh. First of all, the Judeos were not really at the table. As of the Constitution's ratification, most American states didn't allow Jews to hold office.
Second, the religious tradition that influenced the American founding was not Christianity in general but Protestantism in particular -- often in fervent opposition to Catholicism....
If we're going to talk about the important religious influences of the Founding Era we should be referring to our "Protestant heritage," which was quite significant, not our Judeo-Christian heritage....
I think this is more or less correct. We could speak of a broadly defined "Judeo-Christian" or narrowly defined "Protestant Christian" component to the Founding. There was also an Enlightenment component, a Whig component, a Greco-Roman component, an Anglo-Saxon component and so on.
Even the term "Protestant Christian" heritage can mislead. Some folks hear that as the nation was comprised by a vast majority of "born again" Calvinistic reformed Protestants. Nope. Sure there were plenty of them. There were also plenty of nominal Christians who were unchurched and more likely to be in taverns on Saturday nights than churches on Sunday mornings. "Protestant Christian" as a heritage is more important in a cultural, identificatory and minimalistic sense; most folks of that era -- probably around 98% -- thought of themselves as "Protestant Christians" and this includes the uber-orthodox Timothy Dwight as well as Thomas Jefferson who rejected every single tenet of Christian orthodoxy. Both of them could be united under a minimalistic "Protestant Christian" identity. John Adams, a self defined lifelong "Unitarian," bitterly rejected and often mocked doctrines like the Trinity, Incarnation, Atonement and eternal damnation, but was culturally in line with the Puritans of Massachusetts -- his heritage. That's about as far as I am willing to endorse Barry Shain's "Protestant Christian America" thesis.