Chun Han Wong and Lingling Wei, Beijing Probes Top Official; Sun Zhengcai rose to the Chongqing [arty leadership post after Bo Xilai's exit in 2012. Wall Street Journal, July 17, 2017. http://www.theaustralian.com.au/ ... 15c7a2c591126369ed4
("Some party insiders have said Mr Xi may also be trying to block promotion of anyone who coul dbe seen as a potential successor -- a move that would enhance his authority and boost his chances of remaining in the office after his second term expires in 2022")