Zhang Dejiang
In November 2009, Sun was named party secretary of Jilin province, in northeast China. In November 2012, after the 18th CPC National Congress, he was appointed a member of the Politburo and replaced Zhang Dejiang as party chief of Chongqing. The post in Chongqing had emerged as one of the most important regional offices in China, and Sun's assuming the reins in the interior municipality signaled that he was likely destined for even higher office. It also demonstrated the trust that the central leadership placed in Sun, as Chongqing had only a month earlier weathered a political storm with the attempted defection of police chief Wang Lijun and the ouster of party chief Bo Xilai. Since the 1990s, regional leadership tenures were seen as important stepping stones to eventual national leadership.