His father, Ayatollah Ali Khamenei, had turned what was traditionally a religious affairs office into a shadowy national security juggernaut.

Mojtaba Khamenei takes on a role that makes him not only Iran’s spiritual leader but also the highest authority in the land.

With their pervasive military, political and economic clout, the Guards are often considered the main impediment to regime change, or any change, in Iran.

If Mojtaba Khamenei is chosen by Iran’s senior clerics, it may signal a victory for hard-liners, an analyst said.