I am still waiting to crank through Randall Balmer's new book until D. G. Hart's A Secular Faith is published (actually, I think it is available, but it hasn't arrived at amazon.com yet). But this review of Thy Kingdom Come by John Wilson at Books and Culture is absolutely devestating and jibes with my sense of the book after reading the introduction and first chapter.
All that being said, I do think that significant questions can be raised of the current evangelical, accomodationist stance on the relationship between church and state. What we call accomodation (that is, the state should accomodate Christianity in the public square), our secular neighbors seem to read as "theocracy." And if their fear (and our aggressiveness) confuses a position how church and state relate with the nature of the Gospel itself, then perhaps an older model of separation might be better for Christianity in America after all.