From what I read, David Barton is largely a historical revisionist, is this true?
revisionism can mean lots of things. Barton is a guy that has made up sources that don't exist, takes things out of context, and is driven by his ideology and desire to profit. There is a reason he doesn't have a university affiliation: A) his terminal degree is a B.A. and B) His so-called scholarship is a dangerous joke. That said, if you are a fundamentalist who is desperately looking for validation for your beliefs in the past, he's your man.
Here are some places where he "responds" to his critics: http://www.theblaze.com/stories/2012/08/15/david-barton-vs-his-critics-theblazes-extensive-analysis-of-their-claims-thomas-jeffersons-faith/
what do you think?