The media have had a good time lately with Michele Bachmann's double-down gaffe about how the Founding Fathers, including an eight-year-old John Quincy Adams, "worked tirelessly " to end slavery, despite writing it into the Constitution and owning slaves themselves.

Most reporters and pundits seem to assume this is another Palin-class face plant, along the lines of celebrating Paul Revere for warning the British and protecting gun rights . Bachmann is certainly capable of such bloopers, as in her announcement that the American Revolution started in New Hampshire .

But with the Founding Fathers and slavery story, there is a big difference. While Sarah Palin's eye-darting improvs fairly scream "I didn't do my homework," in all likelihood Bachmann did do her homework on this one. It's just that she's reading from a different text than most of us.

Bachmann, like many on the right, is a follower of the self-taught historian David Barton , a leader in a rapidly spreading movement of Christian historical revisionism. Other fans include Mike Huckabee, Glenn Beck, Texas Governor Rick Perry and Louisiana Governor Bobby Jindal.

Barton is, among other things, an evangelical minister, author, former Texas Republican Party vice-chair and the founder of WallBuilders , which describes itself as "an organization dedicated to presenting America's forgotten history and heroes, with an emphasis on the moral, religious, and constitutional foundation on which America was built -- a foundation which, in recent years, has been seriously attacked and undermined."

Among Barton's claims, as recounted in reports by People for the American Way and elsewhere:

• The Founders were evangelicals who intended America to be a Christian nation
• Republicans, not Democrats, have been in the forefront of civil rights progress
• And yes, the Founders worked tirelessly to end slavery.

The Republicans -as-civil-rights-champions argument, by the way, will be familiar to anyone who remembers North Carolina Congresswoman Virginia Foxx's eye-popping 2009 assertion that Republicans, not Democrats , passed civil rights legislation in the 60's.

Barton enjoys little respect from trained historians. He has been found to have faked quite a few of the quotations he has used to show that the founders wanted the Christian church and the state joined, not separated.

His claims about the Founders and slavery are based on uncontroversial evidence that some of the Founders disliked or had mixed feelings about the institution. But he uses that evidence to characterize slavery as a malign inheritance from the British (who ended it well before the US did) that the Founders fought to end, and to claim that liberals have deliberately smeared both the Founders and the Constitution by focusing on the negative side of the slavery legacy.

Barton believes such liberal bias distorts the history taught in our schools. An advisor to the National Council on Bible Curriculum in Public Schools, he was able to play a role in the recent, controversial editing of school history texts in Texas, tilting them towards Christian revisionist, and pro-Republican, views.

The rewriting of history is a natural, and even unavoidable, consequence of the absolutism on both religion and the Constitution that characterizes Tea Party Republicanism, of which Bachmann is now the figurehead. Such absolutism requires believing that the founding text of your creed is complete and perfect, and that its authors were infallible. When reality and belief collide, reality has to give way.

So if the Founders owned slaves, and the Constitution said that was fine, there are only a few choices:

1. Slavery actually wasn't all that bad, or
2. The Founders must have been trying to end slavery, and/or
3. There were more Founding Fathers than you think: we need to include that child prodigy John Quincy Adams.

Of course, there is a hate-crazed fringe that would be fine with some version of option 1. Bachmann is not above dog-whistling to people in or near this fringe, with comments about President Obama being "anti-American ." And neither is David Barton, who has been a guest speaker for the racist and anti-Semitic Christian Identity movement.

But (we can be grateful) option 1 is still off the table. So that leaves options 2 and 3.

But while it's uncontroversial that some of the Founders did not like slavery, it's also uncontroversial, or should be, that:

• Slavery was explicitly protected by the Constitution
• It took eight decades, a Civil War and -- very uncomfortably for Constitutional originalists like Bachmann -- a Constitutional amendment to end it
• And full legal equality for African Americans was not established until the passage of the Voting Rights Act in 1965, under -- more awkwardness -- Democratic President Lyndon Johnson.

Uncontroversial, that is, unless you believe that reality is whatever you need it to be.

This is where Michele Bachmann, and a growing portion of the Republican Party, is coming from: if history doesn't support your beliefs, change history. The same goes for any other body of evidence, whether about climate change, evolution, or the economy.

In 2004, a Bush Administration official famously made a dismissive comment about the "reality-based community " to reporter Ron Suskind. The phrase seemed outlandish to those still in that community, who perhaps had not previously thought of reality as a lifestyle choice. But it was not at all far out to the far right.

The faith-based community they inhabit is not just a spiritual enhancement to reality. It's an alternative.