For those that are not aware, the basic structure of the Iranian system is as follows: The Majlis (parliment) is lead by the President and First Vice President (a function previously served by a Prime Minister). They are overseen by the Guardian Council lead by the Supreme Leader, who is elected and monitored by the Assembly of Experts. However, as the groups do not always agree, the Expediency Council is a sort of mediator between the two. The Majlis, President and Assembly of Experts are all elected, however all candidates must be approved by the Guardian Council. The Council itself contains 6 members appointed by the Supreme Leader, and 6 more selected by the Majlis from a group chosen by the judiciary. The council also appoints a variety of other important positions, such as the leader of the military.
The reason for the extensive oversight by the Guardian Council rests in the philosophy of Islamic Jurists; a group of learned Islamic scholars charged with ensuring the application of Islamic principals. In Iran's case, this includes the interpretation of their constitution, though it is not a court in the sense that it arbitrates between two opposing parties.
Some interesting historical background to the current situation is as follows: Mahmoud Ahmadinejad was the previous President, the questioned victor of the recent election, and favoured by the Supreme Leader, Ayatollah Khamenei (not Khomeini, that was the first Supreme Leader and leader of the Islamic Revolution).
On the other hand, the questioned 2nd place politician is Mir-Hossein Mousavi, who is probably not favoured by Khamenei. This is because when Khamenei was President of Iran, Mousavi was Prime Minister, and it is believed that him and the then Supreme Leader Ayatollah Khomeini worked together to restrain Khamenei's influence. Indeed, one of the very first things Khamenei did when becoming the Supreme Leader was abolish the position of Prime Minister, removing Mousavi from politics. As a result, Mousavi avoided politics for many years until the recent election.
Another interesting element is that of Ayatollah Rafsanjani, who is the current chairman of both the Assembly of Experts and the Expediency Council. Ahmadinejad made some very defamatory remarks about him during the last election debate, leading Rafsanjani to write an open letter to Khamenei comparing Ahmadinejad's statements to that of various discredited groups. The two have been long time political enemies.
Also, as the chairman of the Assembly of Experts, Rafsanjani could initiate the dismissal of the Supreme Leader if it can be shown that Khamenei is violating Islamic tenants. Indeed, by his apparent election rigging and endorsement of the Ahmadinejad before the usual 3 day grace period, it appears some Grand Ayatollahs (Sanei in particular) have issued edicts decrying the election as a falsehood and that supporting it is against Islam. Indeed, rumour has it that Rafsanjani has called a meeting of the Assembly, but his intentions are unknown.
Remember, that Iran is in a tremendous state of flux right now. There are many rumours flying about, so don't trust them as absolute. The recent protests in Tehran alone are estimated to have between 1 and 2 million participants, and are likely to only grow. This kind of mass protest has not been seen in Iran since the Islamic Revolution. In any case, we will have a better of idea of what's happening by the end of the week. Lets hope for something not reminiscent of Tiananmen Square, though I don't think it will get too violent. After all, such government reprisals are part of what fueled the Islamic Revolution to begin with. Khamenei knows this, and indeed there has only been a handful of fatalities so far related to the acts of Basij militas, but that may change. In any case, Iran could clearly use a change of political atmosphere right now.
Personally, I like the Iranian people. They are one of the most industrious and educated populaces in the Middle East. Just look at the wonderful work by Ali Rahimi on GameDev.net. Their progress and development has been remarkable, though there is still much to do. For example, if not for their government's dangerous and inflammatory behaviour, there is no reason why the Iranian people shouldn't have nuclear power. The people are honourable. Their government's active role in destabilizing the region (along with many other parties) is also regrettable. However, these protests show that the Iranian government is no longer reflective of the people's will. Hopefully, that will change.
My prayers are with our friend Rahimi and his country.
The Globe and Mail
The New York Times
Various Twitter feeds (e.g. IranElection09)