Sam Harris is one of these "new atheists" that take a hard anti-theistic stance. Religions tend to have a fundamentalist core that is intolerant of any belief that does not fit their dogma. The idea is that even moderates and other more casual observers of a religion tacitly support that religions fundamentalist core.

It's a sound argument but there are two main barriers of acceptance. First the anti-theists do not acknowledge that religious beliefs (and indeed many unfounded beliefs) are rational. Religious people are not crazy or uninformed. This is a separate issue from having an inconsistent and / or scientifically unfounded belief system.

Second, the anti-theists do not provide much of an alternative. Dawkins seems to say, you guys are obviously nuts, so you must see that you simply have to adopt my world view. It's off putting.

Anyway I've gone from bemused to agnostic to naturalist (a way of saying "atheist" without mentioning theism). I quite enjoy reading these authors ... I just don't see how they'll affect a change.