CLAREMONT, CALIFORNIA – Less than 18 months after becoming General Secretary of the Chinese Communist Party, Xi Jinping is poised to cage the biggest political “tiger” – a corrupt top official – in the history of the People’s Republic. Although rumors of the imminent fall of former internal security chief Zhou Yongkang have been swirling for months, many observers remained unsure whether Xi would prosecute Zhou and thus break the party’s long-established unwritten rule of immunity for sitting or retired members of the Politburo Standing Committee.