The spiritual gap between Iran’s Shia ayatollahs and the people they rule is widening. The strictures of the theocracy and the doctrine of Shia supremacy alienate many. So growing numbers of Iranians seem to be leaving religion or experimenting with alternatives to Shiism. Christians, Zoroastrians and Bahais all report soaring interest. Leaders of other forms of Islam speak of popular revivals. “There’s a loyalty change,” says Yaser Mirdamadi, a Shia cleric in exile. “Iranians are turning to other religions because they no longer find satisfaction in the official faith.”
…The repression isn’t working. The state says over 99.5% of Iran’s 82m people are Muslim. But its numbers are not reliable. A poll of more than 50,000 Iranians (about 90% of whom live in Iran) conducted online by Gamaan, a Dutch research group, found a country in religious flux. About half of the respondents said they had lost or changed their religion. Less than a third identified as Shia. If these numbers are even close to correct, Iran is much more diverse than its official census shows.
Here is more from The Economist. Speculative, but interesting.