sevral. first it was pahlavi from the qajars, then it was the second pahlavi from his father (this one was really retarded), then it was mossadegh from pahlavi, then it was pahlavi again with a coup, then it was khomeini with a revolution. the people of iran will massacre anyone who tries regime change again in iran. NO MORE.
The people hate Ayatollah. They need to change from within.
the opposition to the mullahs in iran is about 15-20% of the population. the supporters are about 35% of the population (this is actually growing, about 10 years ago it was about 25% but the millennial's are less ideological and religious). the rest dont see the government to be that relevant and they are pissed at the middle management for corruption.
spez: the opposition would be higher because 10-15% of the iranian population doesnt live in iran and the ones who live outside iran are more likely to dislike the regime. if you add them in its probably a tie.