In recently thinking about the disagreements–many of them extremely acrimonious and deeply felt–about the presence of the large cross in Maryland to honor fallen soldiers in World War I (which the Supreme Court will pronounce on, but not resolve, shortly), I’ve wondered whether those disagreements reflect a deeper set of conflicts, or whether they instead sit on the surface of relative concord and agreement about American political and social life.

A new book seems to suggest something like the former possibility, that religion very often has been the key or central symbol of our deepest national political conflicts (though I would think race has at least an equal claim). The book is America’s Religious Wars: The Embattled Heart of Our Public Life (Yale University Press), by Kathleen M. Sands. Indeed, even the way that the blurb puts the constitutional status of the wall-of-separation metaphor is a hotly contested matter in American public life.

“When Americans fight about “religion,” we are also fighting about our conflicting identities, interests, and commitments. Religion-talk has been a ready vehicle for these conflicts because it is built on enduring contradictions within our core political values. The Constitution treats religion as something to be confined behind a wall, but in public communications, the Framers treated religion as the foundation of the American republic. Ever since, Americans have translated disagreements on many other issues into an endless debate about the role of religion in our public life.

Built around a set of compelling narratives—George Washington’s battle with Quaker pacifists; the fight of Mormons and Catholics for equality with Protestants; Teddy Roosevelt’s concept of land versus the Lakota’s concept; the creation-evolution controversy; and the struggle over sexuality—this book shows how religion, throughout American history, has symbolized, but never resolved, our deepest political questions.”