True, I think someone like Hillel Nueur who did a lot of human rights work for the Iranians would have a better handle on how much percent of the population actually supports the Mullahs. It seems that they have much less internal support than we are led to believe.
The lack of support is quite clear. Mass protests, public mockery of the regime's rules at sporting events and such, and more.
Within the Jewish community, they toe a difficult line. Kids chant "Death to America" and "Death to Israel" at school every day. Jews speak out against Israel all the time, usually saying "zionists". There has been a crackdown since the massacre, with people leaving group chats that have Israelis on them, homes were raided, and some families had passports confiscated. Some Tehillim for that community is likely on order.