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 Establishment Clause in the U.S. Constitution's First Amendment.

It's worth noting that the Establishment Clause approach did have a successful history. For example, Vashti McCollum's 1948 case resulted in forbidding the use of classrooms for religious instruction and Ellery Schempp's 1963 case resulted in forbidding official Bible readings in public schools. There were also a number of other important cases that similarly challenged the teaching of creationism. However, bringing such church-state separation cases has become increasingly challenging over recent years.

One problem with bringing Establishment Clause cases today is proving that the plaintiff has been sufficiently harmed, that something can be done about it and that they are the right person to bring the lawsuit. This is called "standing," which wasn't always such a barrier. But, a number of recent rulings have made proving it increasingly difficult. And even in cases where plaintiffs do show standing, the courts tend to justify government endorsement of religion as "accommodation," as historically acceptable "ceremonial deism," or dismiss it as de minimus (such as in the "In God We Trust" challenges).

This new case, Jane Doe, et. als. v. Acton-Boxborough Regional School District et al, is unique and important because the state's constitutional equal protection guarantees are the basis of the suit, not the Establishment Clause of the U.S. Constitution's First Amendment. And how convincing is this line of argument? Let's see.

There's plenty of support for this concept in the case law. The Supreme Court said back in 1994, just as government cannot "segregate people on account of their race, so too it may not segregate on the basis of religion." The court also said, "A government cannot be premised on the belief that all persons are created equal when it asserts that God prefers some." Moreover, many state constitutions and nondiscrimination laws expressly forbid discrimination based on religion, giving plaintiffs a remedy against governmental religiosity that is wholly removed from the Establishment Clause.