Former Mexican President Carlos Salinas de Gortari began a hunger strike, demanding that his name be cleared of rumors that he allowed the coverup of an assassination. Salinas said: "It's a question of personal honor." The ex-president's downward slide began Tuesday, when his brother Raul Salinas was arrested for allegedly plotting a high-level murder. Wednesday, he withdrew his candidacy for chairman of the World Trade Organization. Thursday, prosecutors said President Salinas himself could be charged with impeding a probe of another killing -- the March 1994 shooting of PRI presidential candidate Luis Donaldo Colosio, whom Salinas had chosen as his successor. Now, formerly timid critics are blaming him, in part, for the Dec. 20 devaluation that sent the peso plummeting.