贾庆林
It is not clear if Sun had any strong backing from former political heavyweights prior to his ascendancy to the Politburo; more likely, he was a consensus candidate whose loyalties crossed factional lines. It has been suggested that Jia Qinglin or Wen Jiabao may have served as Sun's advocate for promotion; the former because Sun worked for Beijing for much of his early political career, where Jia Qinglin was party secretary, and the latter because Wen and Sun both share a modest upbringing and common concerns for China's rural population.