During my morning reading of the Guardian, I found this sentence in an article by Jonathan Freedland:

America’s centre of gravity has moved rightward, creating a set of shibboleths that cannot be challenged.

Shibboleths? According to the OED, it is a Hebrew word that means "stream in flood", used by Jephthah as a test-word by which to distinguish the fleeing Ephraimites (who could not pronounce the sh) from his own men, the Gileadites (Judges xii. 4-6).
It has come to mean a word or sound which a person is unable to pronounce correctly; a word used as a test for detecting foreigners, or persons from another district, by their pronunciation. In this context, it is used in the wider sense of a catchword or formula adopted by a party or sect, by which their adherents or followers may be discerned, or those not their followers may be excluded.