The "Endorsement" Test as a Constitutional Norm:

Eugene Volokh notes the "endorsement of religion test" might be headed back to the Supreme Court, where they might have a chance to overturn or clarify.

My thoughts: When the Constitution grants rights to "religion," it means just what it says: "religion" -- Christian or not -- or "religious" nor not; just as with race, whatever constitutional rights attach to "religion" equally attach to everyone's religion or lack thereof.

As such, according to the original meaning of the Constitution's text, government can a) endorse any religious principle (i.e., government can say, "under God," "under no God," "under Jesus," "under Allah,") b) endorse no religious principle (i.e, cannot endorse any of the aforementioned concepts), or c) if constitutionally permitted to endorse some religious point of view but not others, since the political theology of America's Founding documents is not Christianity, Deism, or Atheism, but rather a generic theism -- i.e., the laws of nature and nature's God, "ceremonial theism," if you will, a generic Providence inclusive of as many world "religions" (including many non-Christian ones) as possible -- endorse the United States as being "under God," but nothing more.