One of China’s most high-profile politicians, Sun Zhengcai, once seen as a likely candidate to be China’s next leader, was sentenced to life in prison for taking nearly $27 million in bribes.

A court in the northern port city of Tianjin that has become the go-to choice for handling official corruption cases handed down the verdict today (May 8), after the 54-year-old Sun last month pleaded guilty to accepting more than 170 million yuan in bribes from 2002-2017.

Favored by Communist Party elders, Sun was seen as a rising star before he became snared in Chinese president Xi Jinping’s anti-corruption campaign, which kicked off after Xi took power in 2012. It has punished more than 1.5 million corrupt officials over the past five years, and helped Xi exert tighter control over the party. But Sun’s investigation was seen as part of a more far-reaching goal—his fall just months before a key leadership meeting was seen as one of the strongest signals yet in support of rumors that Xi was planning on ruling beyond the conventional 10 years.

In July 2017, Sun was abruptly removed from his post as the party secretary of the inland city of Chongqing, and replaced by a Xi protégé. He was then put under investigation for violating party regulations. It was a sign that Xi “doesn’t feel bound by the order of promotion set by the previous generation of leaders,” a Beijing-based party watcher told the New York Times (paywall) at the time. In September, the party’s internal discipline watchdog formally expelled Sun from the party, saying (link in Chinese) he had become “highly bureaucratic, lazy and ineffective, led a degenerate and corrupt lifestyle, engaged in money-for-sex transactions.” In February, Sun was charged with bribery by prosecutors in Tianjin.

Sun had been seen as a contender for China’s presidency because his career path was following the trajectory of past leaders. In 2012, the then Chongqing party boss became the youngest member of the 25-person Politburo, the party’s top decision-making body. Originally, Sun looked likely to get a further elevation into the party’s innermost circle, the seven-person Politburo Standing Committee, during the party’s leadership reshuffle event in October—until party watchers noticed him missing from a ceremony for his replacement to run Chongqing.

With Sun sacked, Xi ended up picking no one in his fifties to join the standing committee, leaving a vacancy for his potential heir apparent. In March, the Chinese leader moved to abolish the presidential term limits with a constitutional change, dismantling the only institutional obstacle for him to rule for a third five-year term—or for life.

Sun’s case echoes the downfall of his predecessor Bo Xilai, the former Chongqing party boss from 2007-2012, who was also once a power rival of Xi. In 2013, Bo was charged with corruption and sentenced to life in prison, making the leadership of this particular city something of a poisoned chalice.