SACRAMENTO -- With the FBI and a federal grand jury reportedly investigating him, incoming Democratic state Senate leader Don Perata of Oakland almost certainly faces a coup attempt by a Southern California senator who narrowly lost that leadership post to him, sources said Thursday. The ouster attempt might even be staged by another lawmaker as a new, post-election upper house begins work next month, numerous Capitol sources said on the condition their names not be used. Removal of Perata from the post of president pro tem -- the second-most- powerful elected job after the governor -- would leave the Bay...