REUTERS/Khalid al MousilyBAGHDAD (Reuters) - Hundreds of supporters of Shi'ite Muslim cleric Moqtada al-Sadr stormed into Baghdad's Green Zone on Saturday and set up tents beside parliament after Sadr denounced politicians' failure to reform a political quota system blamed for rampant corruption. The protesters, who had gathered outside the heavily fortified district housing government buildings and many foreign embassies, crossed a bridge over the Tigris River chanting: "The cowards ran away!" in apparent reference to departing lawmakers.