But the biggest obstacle to establishing the Caliphate in California is that Shi'a "Islam" never bought into the Caliphate at all. At bottom, it's a different religion from Sunni Islam. They're not just different branches of a faith, as with Protestantism and Catholicism, but separate faiths whose core differences are more-pronounced than those between Christians and Jews.One place where I do question the author is on his suggestion that the European influence stamped Protestantism. I would rather suggest that Roman Catholicism has a similar problem with Shi'a Islam: that it was very strongly influenced by the Roman religions of the time, whence comes what appears to be its polytheism and idolotry to us Protestants.
Technically, Sunni militants are correct when they label the Shi'a "heretics." Persians and their closest neighbors, with long memories of great civilizations, were never comfortable with the crudeness of Arabian Islam--which the anthropologist Claude Levi-Strauss aptly called "a barracks religion."
The struggle has never ended between the ascetic, intolerant Bedouin faith of Arabia, with its fascist obsession on behavior, and the profound theologies of Persian civilization that absorbed and transformed Islam. While Shi'ism only prevailed in Persia within the last millennium (nudging out Sunni Islam at last), "Aryan" Islam had long been shaped by Zoroastrianism and other ineradicable pre-Islamic legacies.