They just want to confuse us. Maybe because he sounds so sincere, and because few people bother to check out his misrepresentations, and mostly because he is saying what a lot of people want to believe (no matter that it's utterly false), too many folks cheer him on.
The Most Influential Evangelist You've Never Heard Of : NPR
Suppose (though it's not true) that the founders, including Jefferson, were as conventionally religious as he claims. So what? That was 1787, this is 2012, we have a lot better explanations today of the origin of the universe and everything else. But in fact, even with the more limited knowledge available to them, most of those men were skeptical enough to realize that there were no simple answers, and certainly no sect could claim to have them.