Mark LeVine has these thoughts:
… regardless of whether there was significant fraud the power elite could decide collectively that the protests are not motivated by broader concerns and thus do not threaten the stability of the system.You can read his entire article here.
This could also lead them to agree to a broad recount or run-off, even at the risk of a Mousavi win, and it is worth mentioning here that Mousavi is no liberal; the "core values" of Khomenei's revolution - to which he advocates a return - are well within the mainstream of Iran's clerical culture.
Alternatively, if the protests do not lose steam in the coming days, the leadership could decide that the opposition is too broad and deeply rooted to attempt to crush it.
In this case, it would have little choice but to cave in to the protesters' demands or face losing its legitimacy in the eyes of the broader Iranian public, particularly if large numbers of protesters are arrested, injured or killed.
The greatest degree of uncertainty surrounds a scenario in which the power elite both concludes that the mass protests reflect deep-seated discontent by a large segment of the population, yet at the same time believes it has a narrow window of opportunity to deal with this situation forcibly before losing control to the rapidly encroaching street politics.
In this case, Iran could quickly approach a Tiananmen moment, in which the Iranian government calculates that crushing the pro-reform opposition will give it time to push the reformers back in the closet for the foreseeable future, and push the cosmopolitan liberal-cultural elite who have the ability to leave, to do so.
The problem is that Iran can't follow China's path.
It is true that if oil prices continue rising, they will produce enough revenue for the government to keep the poor and working classes happy, or at least quiescent.
But what allowed the Communist party in China to maintain its hegemony rather than merely dominance over Chinese society was its willingness to liberalise culturally at the same time as it closed down politically.
Cultural liberalisation became the safety valve that allowed the emerging generation of Chinese citizens to accept the continued power of the Communist party.
Needless to say, no such safety valve exists in the Islamic Republic, where a cultural perestroika is precisely what Ahmadinejad and his supporters in the leadership and among the people want to prevent.
In China the government struck a bargain with the people, telling them: "You can do whatever you want as long as you don't challenge the power of the state."
The Iranian government has over the last two decades negotiated a very different and more narrow bargain with its citizens: "You can do what you want behind closed doors, as long as you keep the music down. But we own the street and the public sphere. So put your headscarf on before you leave the house, and don't think about challenging cultural or political limits publicly."
That bargain has now collapsed as hundreds of thousands of Iranians have, at least for the moment, reclaimed the streets.
If Ahmadinejad has been railing against "velvet revolutionaries" since he took office, he is today counting on the situation in Iran resembling the Czechoslovakia of 1968 rather than 1989.
Yet with one of the world's youngest populations and an increasingly urban, educated and sophisticated citizenry, it is hard to know how long the Iranian government can continue to impose its conservative moral values upon a bourgeois-aspiring, culturally open technocratic class whose expertise and loyalty will be crucial for Iran's long-term social, economic and political development.