TOKYO -- In a surprise move that sent shock waves through China's political sphere, the Communist Party announced on July 15 that Sun Zhengcai, once a front-runner of the next generation of leaders, had been removed as Chongqing party chief.
His replacement was Chen Min'er, a protege of President Xi Jinping, and party chief of Guizhou, a relatively poor and economically backward province.
Party chiefs in provinces and cities are the top officials of their regions. While the 53-year-old Sun is one of the party's 25 most powerful Politburo members, 56-year-old Chen is still just one of the party's 200 or so Central Committee members.
Sun was placed under investigation by the Central Commission for Discipline Inspection, the party's top anti-corruption body.
It is still uncertain whether he will eventually be punished. Chinese state media reports on July 15 still referred to Sun as a "comrade." But in an ominous sign for Sun, Chen made no mention of his predecessor's performance when he delivered his first speech in Chongqing.
The political fate of Sun will have a significant impact on a party leadership reshuffle at the party's next quinquennial national congress this autumn.
The Politburo Standing Committee, the party's top decision-making body led by Xi, is to be shaken up at the national congress. Most of the current seven committee members are supposed to retire because of their age, although Xi and Premier Li Keqiang will stay on.
Every summer, China's current leaders, including Xi, and retired party elders get together in the seaside resort of Beidaihe in Hebei Province to informally discuss important issues.
The formation of a new party leadership team will be high on the agenda at this year's closed-door "Beidaihe meeting." Sun's fate will become clear by around mid-August, when the conclave is to end.
Nobody knows what lies around the corner in today's Chinese politics. Even those seen as sure leadership candidates cannot feel completely safe. The reality is that such hopefuls may be in the greatest danger.
History repeats itself
What happened to Sun seemed like a deja vu from five years ago.
Bo Xilai was the high-flying party chief of Chongqing until his wife killed British businessman Neil Heywood in November 2011, marking the first in a series of incidents that led to Bo's fall from power.
In February 2012, Wang Lijun, Bo's henchman and Chongqing's top security official, sought refuge at the U.S. consulate general in Chengdu, Sichuan Province after falling out of favor with his boss. Fearing for his life, Wang approached the consulate dressed as a woman.
Bo was Xi's rival and posed a serious threat to the then-leader-in-waiting. When Bo was removed from his post on March 15, 2012, as with Sun, he was initially still referred to as a "comrade" by Chinese official media.
But less than a month later, on April 10, it was announced that Bo had been suspended as a Politburo member for serious disciplinary violations and placed under formal investigation by the Central Commission for Discipline Inspection. He was eventually sentenced to life in prison.
Will Sun face the same fate?
In China, major scandals are always linked to political upheavals.
In April, Xi chose to be elected as one of the Guizhou delegates to the party's upcoming national congress. In past party congresses, Xi had taken part as a delegate from Shanghai, where he had served as party chief until his promotion to the top echelon.
The selection of Guizhou this time was to demonstrate his confidence in Chen. In hindsight, it was also a prelude to Chen's big promotion.
Around the same time, a dark cloud began to hang over Sun, with He Ting, Chongqing's vice mayor and top security official, suddenly disappearing from the public eye as he was detained. Sun and He both hail from Shandong Province.
There was another important incident in February, when a visiting "inspection team" dispatched by the Central Commission for Discipline Inspection to Chongqing harshly criticized the province's condition.
"The harmful thoughts of the Bo Xilai-Wang Lijun era have not been eliminated completely," the team said bluntly.
The Central Commission for Discipline Inspection is headed by none other than Wang Qishan, a key political ally of Xi and a Politburo Standing Committee member.
Xi came to power as the Communist Party's general secretary at the party's last national congress in late 2012. He became president in the spring of 2013.
Since taking power, Xi has been using his sweeping anti-corruption campaign as a tool to fight his power struggle with political foes and consolidate his power.
Wang Qishan is spearheading the anti-corruption crusade, which has already netted many influential figures.
Another blow to Sun came earlier this year when rumors about the close relations between the wives of Sun and Ling Jihua swirled across the country. Political observers raised questions about Sun's fate.
Ling was a close aide to former Chinese President Hu Jintao. Ling fell from power and was sentenced to life in jail after being accused of corruption.
China's anti-corruption czar
"What happened to Wang Qishan?"
People started to talk about Wang's disappearance from the public eye in May and June. No media coverage was given to the top Chinese graft buster's movements during that time.
This sparked a torrent of speculation about Wang's whereabouts both at home and abroad, with some saying he might have fallen from power.
The truth is that Wang was inspecting Guizhou in May and June, accompanied by Chen, then party chief in the province and Xi's protege.
The purpose of Wang's inspection tour was to conduct a final check on Chen before promoting him to party chief in Chongqing, a post usually reserved for a Politburo member.
Wang was sizing up Chen to determine if he was suitable to become a candidate to succeed Xi as China's top leader in the future. Wang also wanted to make sure Chen was free from any scandals.
That Wang was deeply involved in the designing of the new party leadership team speaks volumes.
On July 17, two days after the replacement of Sun by Chen was announced, the People's Daily, the mouthpiece of the Communist Party, published a long article penned by Wang himself stressing the role of inspection teams and the importance of continuing the tough corruption crackdown.
Wang praised Xi in the article, referring to him as the "core of the leadership," in a clear sign that their alliance remains solid.
Xi and Wang are poised to continue to push ahead with the Xi regime's signature anti-corruption campaign and completely wipe out what they regard as the harmful legacies and influence of Bo, Ling and Zhou Yongkang.
Zhou, a former Politburo Standing Committee member, was also purged in Xi's anti-corruption drive and sentenced to life in prison. Bo, Ling and Zhou were all Xi's political foes.
On another front, a separate inspection team was dispatched to the prestigious Peking University recently as part of efforts to root out those sympathetic to Bo and Ling.
Bo is a Peking University graduate. Ling's son also attended the university before being killed when he crashed his Ferrari. Ling's wife is also said to have had cozy relations with a company affiliated with the university.
Xi's relentless purge of rivals is also an attempt to silence outspoken party elders, as they seek to influence the formation of the new leadership team at the Beidaihe gathering. Such party elders had close relations with Bo, Ling and Zhou.
After Bo's downfall in 2012, Zhang Dejiang concurrently served as the party chief in Chongqing. Later that year, Zhang became a Politburo Standing Committee member at the party's last national congress.
Zhang currently serves as chairman of the Standing Committee of the National People's Congress.
It will not be easy for Chen to get promoted to the Politburo Standing Committee at the party's next national congress this autumn.
Chen is currently not a Politburo member but a lower-ranked Central Committee member. He will have to leapfrog many rivals if he is to join the all-powerful committee.
But by being appointed to Chongqing's new top official, a major position in China's leadership, there can be no doubt that Chen has joined the shortlist of candidates qualified to succeed Xi.
In stark contrast with Chen, Sun, who is close to former Chinese Premier Wen Jiabao, has dropped out of the succession race.
Xi's proteges now hold top-level posts in China's four municipalities -- Beijing, Shanghai, Chongqing and Tianjin.
Cai Qi, Xi's close aide, serves as the party chief in Beijing. Li Hongzhong, who has cozied up to Xi, also serves as the party chief in Tianjin. Shanghai's mayor is Ying Yong, who has been Xi's close aide since the latter's time in Shanghai.
The lone outsider is Hu Chunhua, the 54-year-old party chief in Guangdong Province, a protege of former President Hu Jintao.
Political forces within the Communist Party are broadly divided into three groups -- Xi's group, the Communist Youth League faction, and former President Jiang Zemin's group.
The Communist Youth League is the party's massive youth organization. The group has been led by former President Hu and incumbent Premier Li. Hu Chunhua also belongs to the faction.
Chen's meteoric rise
China's succession race has become even more difficult to predict. This is exactly what Xi wanted when he drove Sun out of the race. The guessing game over Xi's future successor will continue.
If Xi follows customary practice, he will now have to narrow down the candidates to succeed him. Xi himself emerged as a shoo-in to take over from Hu Jintao as the party's general secretary and Chinese president at the 2007 party congress.
But any organization will see its top leader's gravity erode when an heir apparent emerges. If Xi is to avoid the same fate, he must handpick his successor carefully.
That is why Xi intends to make multiple candidates, including Chen, so they can spend time competing in the succession race.
Chen was born in Zhejiang Province. He became president of the Zhejiang Daily Press Group when he was still in his 30s. After Xi was assigned to the province, Chen supported Xi as his speech writer.
In the past, Chen has been seen as a dark horse candidate to succeed Xi in the future. He is no longer just a dark horse, but his future is still far from guaranteed.
During the annual session of the National People's Congress, China's parliament, in Beijing this March, Chen attended an open session and held a lively press conference. Beaming with confidence, he used grand gestures to point to reporters to ask questions.
But Chen overreached himself. Toward the end of the press conference, one reporter doggedly kept trying to ask him a question. Chen pointed at the reporter, accepting his question.
After realizing that the reporter was from Hong Kong, Chen declined to answer the question, cut the reporter off in mid-sentence, and abruptly ended the press conference.
Chen was probably playing it safe and feared he might face a difficult question related to domestic politics at a politically sensitive time. Chen's behavior caused a stir at the venue of the press conference, leaving a sour aftertaste.
Over the next five years, Chen's every move will come under scrutiny both at home and abroad. The peak of the mountain is so near yet so far.