I've read a number of reviews of the book by friends and colleagues, including a brief one by Jerry Coyne that forms part of a more general post on Faircloth's activities. I can endorse this para, which forms the main part of Jerry's review:
The book paints a scary picture of how, despite America’s official policy of church/state separation, our laws and our legislators are still deeply imbued with irrational religiosity. (Read his summaries of the 50 most religiously insane American senators and representatives.) It’s also very eloquent and convincing about how the “Founding Fathers” of America—people like Thomas Jefferson, James Madison, and Benjamin Franklin—were by no means religious, but were at best agnostics, and certainly did not form the U.S. government on Christian principles. That’s a must-read section if you want to go after the common religious claim that “America was founded as a Christian nation.”
Jery also has some mild criticisms. One is that "his [Faircloth's] prescription for how to create a secular America seems appears to consist almost entirely of helping the SCA [the Secular Coalition for America] or donating money to it" - which is a bit unfair to Faircloth. The latter does, indeed, ask us to support the SCA (most specifically on page 132), but he also sets out clear objectives and policies that he asks readers to embrace. If he succeeded in getting a significant number of readers to adopt some version of these ("some version" because I don't claim that the objectives or policies are perfect; obviously, readers ought to think about them), he'd have performed an important service for secularism.
Jerry also suggests that the chapter on sex is "a tad excessive, almost obsessive". Hmm, I was expecting to disagree, given the opinions I am about to express. But to my surprise, I don't entirely. Jerry has a point here: the chapter really could have done with a bit of editorial tightening up.
On the other hand, and more importantly, I actually applaud Faircloth for taking on this controversial issue. Faircloth states clearly, and shows in some detail, that one of the greatest problems with religious morality is its miserable and officious attitude to sexual pleasure. That's a good thing to emphasise - and a brave thing to say, when so many non-believers appear unwilling to take such an unequivocal pro-sex stance. If the result is a chapter that contains a bit of repetition and other such looseness, that's not so terrible. The reader still gets a good deal.