With the Iranian elections coming up very shorly, it's a good time to look at the role of the Supreme Leader and the politics of the man who currently occupies that role. Ali Khamanei, as Supreme Leader, is the most powerful person in Iran. However, he relies on a complex network of patronage and influence, and is himself constrained by other powerful interests. Little of known of his personal politics outside of Iran and Karim Sadjadpour, in this video, outlines some consistent themes from his speeches and actions.
Khameini, a fairly low-ranking cleric, got the job of Supreme Leader over other more qualified choices. Ayatollah Montazeri was often considered Khomeini's successor, but in the end Khameini was chosen. That much everyone knows. But how did Khameini get there and how has he kept his influence? Sadjadpour gives some insight into that.
Update: Mehdi Khalaji looks at Khameini's history and his role in the 2009 Iranian presidential elections.