But as Mr. Sadr has taken a more active role in the government, as many as a third of his militiamen have grown frustrated with the constraints of compromise and have broken off, often selling their services to the highest bidders..
...six major leaders here no longer answer to Mr. Sadr’s organization, according to the intelligence official. Most describe themselves as Mahdi Army members, the official said, and even get money from Mr. Sadr’s organization, but “are effectively beyond his control.”
Sadr has modeled his organization on Hezbollah. However, he may have misunderstood the raison d'etre of Hezbollah, which is its ability to win 4G wars against encroaching nation-states. This ability provides it with the legitimacy they need to persist and prosper. Its relief efforts and good works are secondary to military power, and help to balance the organization's image. Political power, at the state level, comes in a poor third (and only serves to provide cover to the organization, despite its non-state status) -- for good reason, political power in a fractured state is of little meaningful value (unless you enjoy failure and frustration).
Frankly, if Sadr has inverted this equation and placed political power in the first position, he will quickly find himself without much of a militia left. This is particularly true if Sadr's militia isn't really cohesive like Hezbollah -- most signs point to this -- and it tends towards open source. In that case, the lack of a plausible promise (like: "kick the Americans out") will fork the movement. How could he reverse the slide? Given that 4GW military power is the only source of meaningful legitimacy he can tap, the way to gain power (not official control, but defacto) would be to set himself against the US military. The US is an enemy all can agree on, and any military action against US forces would be likely inflate Iraqi nationalism (a secondary loyalty) across the spectrum. I detailed one way to do that: by blocking its supply lines using a defensive grid (as demonstrated by Hezbollah against Israel) last week. I wonder when (or if) he will figure this out?