On April 6, 2015, Hong Kong Oriental Daily Online published a commentary analyzing the current political situation in China using the historical analogy of the Qing Dynasty’s "Eight King Government" coup against Emperor Yongzheng. At that time corrupt officials had severely weakened the country. Yongzheng tried to push through new policies to rebuild the country’s wealth and to consolidate power. He then faced severe resistance from the officials. The "Iron Hat Kings"  even attempted a coup to nullify Yongzheng’s power. Eventually Yongzheng won the fight.
According to the article, Xi’s situation is similar. The group of power holders apparently did not want to give up their vested interests, so, during Hu Jintao’s era, this group created the structure of nine members at the CCP’s power center – the Politburo Standing Committee – and let each member manage an area on his own. When Xi Jinping succeeded Hu, the "Nine Presidential System" or the "Nine Politburo Standing Committee Members System" was changed to the "Seven Politburo Standing Committee Members System," but still, those power-holders tried to block Xi from using his authority.
Though Xi Jinping’s authorities have taken down Zhou Yongkang, Xu Caihou, Bo Xilai, Ling Jihua, and a number of others, "Xi has not dug out the mastermind who set up the ruling system of Nine Politburo Standing Committee Members for the purpose of manipulating the ‘Iron Hat Kings.’" If the new authorities do not take down the ‘Iron Hat Kings" that represent those power-holder groups and do not dig out the mastermind behind it, the anti-corruption campaign will not win a ‘landslide victory,’ and China’s new government will not move forward." "Right now, the Chinese people are looking forward to the early arrival of the (Xi Jinping’s) ‘landslide victory.’" 
The article stated that this power-holder group started in 1989, which implicitly but clearly indicated that Jiang Zemin, who moved to the top leadership position in 1989, was the culprit that created this system to restrain his successors.
Source:  See the Chinascope article at
 Hong Kong Daily Online, April 7, 2015: