Here are a few of the stories that came from the Blaze TV Glenn Beck show on Jan 15 (some video clips inside stories). they are well worth the time to read/watch:
Do You Know the History of the NRA and the 2nd Amendment? David Barton’s Fascinating Lesson

Barton was discredited.
No, Barton has never been discredited, people have only said he was and then acted accordingly. Barton references everything he cites. I have one of his books and I chased down over 100 of the 300+ citations before I gave up — because everything he had said was exactly what he claimed. Heck, girl, he even posts pictures of the original documents on his web site. He owns the largest private collection of original founding documents in the world, second only to the Library of Congress. So think about it: they HAVE to “discredit” him or they will have their heads handed to them but objective reality.
If you repeat a lie often enough, people begin to think it is true. I had the same experience with Barton, though I didn’t follow quite as many citations. He may not have a PhD in history, but being self-taught doesn’t mean he’s wrong.