The whole idea of swearing an oath, especially on a holy book, is a hangover from a belief system in place at the time the Constitution was written.
Hardly anybody today, even quite religious people, believe their soul is doomed to eternal hellfire if the swear falsely on a holy book. A couple of centuries ago, an oath like this actually meant something beyond making one "liable to the penalties of perjury."
Anybody know the procedure in Muslim countries or under Sharia?
How to cook a Frog
Put pot of cold water on stove
Add frog
Turn gas on LOW
WAIT
Get my drift????