If you pay attention to Tea Party politics at all, you’ve probably heard the phrase “constitutional conservative.” It’s supposed to invoke a certain fealty to the principles of the Founding Fathers: “As a constitutional conservative,” said Rep. Michele Bachmann in 2011, announcing her presidential run, “I believe in the Founding Fathers’ vision of a limited government that trusts in and perceives the unlimited potential of you, the American people.”

It’s tempting to treat the phrase as mere rhetoric, but—as Ed Kilgore explained in the New Republic at the time—that’s far from the case. “[Constitutional conservatism] commonly connotes an allegiance to a set of fixed—eternally fixed, for the more religiously inclined—ideas of how government should operate in every field,” he wrote. “Constitutional conservatives think of America as a sort of ruined paradise, bestowed a perfect form of government by its wise Founders but gradually imperiled by the looting impulses of voters and politicians.”

This isn’t ideology as much as it’s theology, transferred to politics. In particular, it’s the “premillennialism” of fundamentalist Protestantism, which holds Eden as the pinnacle of human existence, and sees the present (and the future) as a hopeless corruption to be abandoned with the return of Christ and the rapture of the faithful.

Let’s ignore its merits as a theological approach; as an approach to history and politics, it’s an impossible sell. In 18th-century America, women were second-class citizens, natives were driven from their land, and blacks were enslaved as a matter of course. And the founders, as self-interested elites, codified this in the Constitution with limited voting rights, disregard for Native Americans, protection for the slave trade, and a compromise that made slavery a political boon for slave-owners.

The only way to balance this with constitutional conservatism is to pretend the founders were moral demigods who met and surpassed the challenges of their time. It’s why Bachmann could say, with a straight face, that the founders “worked tirelessly until slavery was no more in the United States,” blind to the fact that George Washington held slaves and Thomas Jefferson was an innovator in the world of slave torment and slave labor. And it’s why, last week, Heritage Foundation President Jim DeMint—who also calls himself a constitutional conservative—could give this gobbledygook take on American abolitionism:

Well the reason that the slaves were eventually freed was the Constitution, it was like the conscience of the American people. Unfortunately there were some court decisions like Dred Scott and others that defined some people as property, but the Constitution kept calling us back to ‘all men are created equal and we have inalienable rights’ in the minds of God. But a lot of the move to free the slaves came from the people, it did not come from the federal government.

It came from a growing movement among the people, particularly people of faith, that this was wrong. People like Wilberforce who persisted for years because of his faith and because of his love for people. So no liberal is going to win a debate that big government freed the slaves. In fact, it was Abraham Lincoln, the very first Republican, who took this on as a cause and a lot of it was based on a love in his heart that comes from God.