Breaking news! Sadr hates America!
He has long been hoping to become Head Goon in Iraq, or more precisely, Chief Iranian Buttmonkey in Iraq. He routinely organizes marches like this, but his militia isn't doing so well right now. They are currently being peeled out of Diwaniyah, where many of them went after they fled Baghdad. At least two bomb factories and many caches of IEDs have been found in the process. Sadr is still hiding out with his buddies in Iran.