This week the American Humanist Association argued a potentially groundbreaking case in Massachusetts Superior Court challenging the state's use of "under God" in the daily, school-sponsored Pledge of Allegiance. Not only might it lead to the state's schools dropping the "under God" version of the Pledge from their daily patriotic exercise—and be extended to similar Pledge cases across the country—it may also be the foundation for new cases challenging government's use of religion to discriminate against atheists and agnostics.

Sure, this isn't the first case challenging the McCarthy-era addition of religious language to the Pledge. But previous attempts focused upon how the religious language inappropriately entangles government with religion, relying upon the...