There's been a debate in evangelical circles between David Barton and a number evangelical historians. It revolves around a book Barton wrote on Thomas Jefferson titled, "The Jefferson Lies: Exposing the Myths You've Always believed about Thomas Jefferson." His book was published by Thomas Nelson, an evangelical publishing firm. The controversy led them to pull his book from distribution.
Barton isn't backing down. He points out that his claims are heavily documented. Glen Beck is a fan of Barton and recently had him on his TV show. Barton showed how much of the documentation for his book was pulled by Nelson before publication.
Another point of controversy was Barton's view that Jefferson opposed slavery even when he owned slaves. Barton says the laws of the time restricted his ability to free his slaves. He explains his views here.
I haven't had a chance to dig into all the criticisms of his book, so I can't say how much is basically a disagreement on the interpretation of historical facts. I suspect most of it is.
I think this sort of debate is healthy. If David needs to tighten up or clarify his conclusions, this will allow him to do so. On the other hand, this debate may well expose some of the faulty, revisionist assumptions made by modern historians on the actual beliefs of Thomas Jefferson.