As I show in my recently published Did America Have a Christian Founding?, an originalist understanding of the Establishment Clause does not require governments to scrub religion from public spaces. The erection of building and monuments containing religious language, images, and symbols is, to borrow from Chief Justices Warren Burger’s opinion in Marsh v. Chambers, “deeply embedded in the history and tradition of this country.” When buildings and monuments are erected should not be, from an Establishment Clause perspective, decisive.
Civic friendship and prudence should inform decisions about the use of religious symbols today. America is far more diverse than it was 100 years ago, so it would be inappropriate for a government to erect a massive cross to honor U.S. military members from different faiths. On the other hand, it is both constitutional and fitting to include crosses, stars of David, and other religious symbols in the 9/11 Memorial. The Establishment Clause does not require a religion-free public square, no matter how many times the Freedom From Religion Foundation insists that it does.Also check out the dialog between Dr. Hall and Dr. Ellis West in the comments.