Opinion | China’s Power Politics

While Mr. Zhou is Mr. Xi’s biggest and most recent target, just a month earlier, on June 30, Gen. Xu Caihou, formerly the most powerful figure in the People’s Liberation Army, was handed over to prosecutors to face charges of corruption. Only now, with both men officially destroyed, can Mr. Xi safely say that he is in control of a system where power still flows from the barrel of a gun.

General Xu will probably be courtmartialed for bribes allegedly received in exchange for promotions, and Mr. Zhou will be tried in connection with the massive empire that his relatives built on the back of inside oil deals. But behind closed doors, they may also be accused of political transgressions like conspiring to protect the first Politburo “tiger” who was in Mr. Xi’s sites: the former Chongqing party boss Bo Xilai, whose rising political power was seen as a threat to Mr. Xi before he was sentenced to life in prison last year for corruption and abuse of power.

Each of these three men — the police chief, the general and the potential challenger — were very badly behaved and dangerously capable of mobilizing political power to serve their own needs. They were three “tigers” who were guarding an edifice of patronage, money and potential violence that had been developing for 25 years.

The center pole of this faction was Jiang Zemin, the former president who came to power in 1989 and refused to fully hand over the reins to his successor, Hu Jintao, in 2002. In the years since, he has insisted on participating in key decisions, protected corrupt leaders and brokered deals, including the elevation of Mr. Xi.

Whatever Mr. Jiang’s earlier expectations in supporting the rise of Mr. Xi, the new president has shown that he will not rule in any former leader’s shadow. Mr. Xi’s step-by-step destruction of Mr. Jiang’s three most dangerous protégés has been a display of cunning and decisiveness that has not been seen since Mao.

It can be difficult to comprehend that Mr. Xi can be serious about fighting corruption and saving the regime, rather than just accumulating power for himself, when his own siblings have accumulated enormous wealth through crony dealings, as forensic investigations by Bloomberg and The New York Times have revealed. But internally Mr. Xi is seen to have moral standing because he has opposed his siblings’ business dealings and ensured that he, his wife and his daughter are clean — as best as any outsider can tell.

Mr. Xi and his close supporters, who were born into the Communist aristocracy as children of former leaders, have won the first round in their battle to save the revolution that their parents fought for. But there is a long journey ahead not least because, like their forebears, they have invested far more effort defining enemies than objectives.