Religion has become a charged token in a politics of division. In disputes about faith-based social services, public money for religious schools, the Pledge of Allegiance, Ten Commandments monuments, the theory of evolution, and many other topics, angry contestation threatens to displace America's historic commitment to religious freedom. Part of the problem, the authors argue, is that constitutional analysis of religious freedom has been hobbled by the idea of "a wall of separation" between church and state. That metaphor has been understood to demand that religion be treated far better...