PORT-AU-PRINCE, Haiti — Police fired tear gas outside the ruins of Haiti's national palace Monday to control 2,000 demonstrators calling for President Rene Preval's resignation in the largest political protest since the Jan. 12 earthquake. Trucks filled with riot police rolled behind the protesters as they jogged past tarps and shanties shouting insults at Preval, who has been criticized for his low profile following the quake and for allegedly using the destruction as a pretext to stay in office beyond his term. "He is profiting from this disaster in order to stay in power," said Herve Santilus, 39, a sociologist who was laid off a few weeks after the magnitude-7 quake struck and has not found work since. Many demonstrators identified themselves as supporters of former President Jean-Bertrand Aristide, who was exiled to Africa aboard a U.S. plane during a 2004 rebellion. Protesters marched to the national mall following speaker trucks that trumpeted calls for Aristide's return.