“THE wall between state and church”, Justice Hugo Black wrote in Everson v Board of Education, a case from 1947, “must be kept high and impregnable”. Justice Black was quoting a line Thomas Jefferson used in 1802 to reassure a group of Baptists that, as president, he would protect the religious liberty of minority sects. The well-pedigreed wall metaphor (Jefferson had borrowed it from Roger Williams, a 17th-century Puritan theologian) is centuries old, but it is becoming less and less apt as a description of the unique relationship between America’s religions and its state institutions. What’s going on?

Government programmes are not completely barred from touching places of worship: it is not an “establishment of religion”, Everson held, for states to subsidise the cost of busing children to parochial schools as well as to public ones. In the nearly 70 intervening years, the Supreme Court has issued a gaggle of rulings on the meaning of the First Amendment’s “establishment clause”. Prayer in school has been ruled out, as have stand-alone nativity scenes inside government buildings. But crèches, crosses and Hanukkah menorahs in public squares have been deemed acceptable. Meanwhile, monuments to the Ten Commandments have been subjected to a Solomonic split decision: such displays are fine near a capitol building but forbidden outside a courthouse. Such microscopic distinctions often come in the form of split decisions. But in recent years, the wall of separation—never quite as sturdy as Justice Black described it—has taken on a few more cracks.

American courts have resisted putting the brakes on purely ceremonial religious references in government contexts. “In God We Trust” is staying put; nor will the judiciary admonish presidents for asking God to bless America. Chaplains delivering benedictions in Congress and in state legislatures are common and, since the Marsh v Chambers ruling in 1983, constitutional. But in 2014, the Supreme Court significantly narrowed the scope of the establishment clause in Town of Greece v Galloway, a case asking whether a town board may open its monthly meetings with sectarian prayers delivered by local clergy. By a 5-4 vote, the court decided that the tradition passed constitutional muster. As long as the prayers do not “denigrate” attendees, threaten them with “damnation” or attempt to “proselytise” the audience, Justice Anthony Kennedy wrote, no harm is done. What of the evidence that the plaintiffs (Jewish and atheist residents of the town) saw themselves treated as “second-class citizens” and felt coerced to join in the supplications? Occasional slights “do not despoil a practice that on the whole reflects and embraces our tradition”, Justice Kennedy maintained.

In dissent, Justice Elena Kagan argued that the majority’s position ignored the “norm of religious equality” at the heart of the First Amendment and was blind to the prayers’ “capacity to exclude and divide”. To judge by the recent decision of a three-judge panel at the Fourth Circuit Court of Appeals, which drew heavily from the Town of Greece ruling, her assessment was on target. Two of the three judges found no constitutional problem with a board of commissioners in North Carolina whose five members personally rise to recite explicitly Christian prayers at their bi-monthly meetings. Somehow, elected officials asking citizens to join them in prayers recognising the Virgin Birth and identifying a life of devotion to Jesus Christ as the “only...way to salvation” is to be taken as something other than a government act “respecting an establishment of religion”. The plaintiffs in this case are likely to ask the entire Fourth Circuit bench to hear the case again. Win or lose, the issue is likely to land at the Supreme Court. With an eight-member court split 4-4 on the question, the eventual ninth justice is likely to determine whether the latest hole in the wall separating church from state will be mended—or enlarged.