Why on earth should Iran become ANY kind of religious republic?
A better model is India, which manages to continue despite frictions between the dominant religions there -- and I might add that things weren't always so very cozy here in the States either. And a true Iranian republic would probably look much more like the Indian or Israeli model -- lots of parties, continual bickering and shifting alliances.. but working.
(And maybe better than our alleged "two-party" system does today. But that's a rant for another thread.)
Indian and Israeli model works only because the majority in those countries are Hindu and Jewish respectively.