Mr. Ren was never a typical liberal; he disdained the protesters who occupied Tiananmen Square in 1989. But as Mr. Xi has amassed power, Mr. Ren’s posts reflected growing irritation with the authoritarian turn in politics.
The current skirmish began last month after Mr. Xi made highly publicized visits to the three main Communist Party and state news organizations to reinforce a new policy: State media must “speak for the party’s will” and “protect the party’s authority,” he said.
As Mr. Xi bathed in the adoring news coverage of his pronouncements, Mr. Ren fired off a few gruff comments to his nearly 38 million followers on Sina.com Weibo, China’s equivalent of Twitter.
“When did the people’s government turn into the party’s government?” he wrote in one post.
“Don’t use taxpayers’ money to do stuff that doesn’t provide services to the taxpayers,” he wrote in another. “The people have been tossed into a forgotten corner.”
Until these remarks, Mr. Ren, 65, had seemed to be at least partly protected by his elite status in the Communist Party as the son of a senior revolutionary who became a vice minister of commerce. He went into business, first selling rabbit pelts, as Deng Xiaoping’s market reforms were coursing through China in the 1980s, and later built a fortune in real estate.
He is also a friend of the party’s powerful anticorruption chief, Wang Qishan, a relationship that has raised intriguing questions about the possibility of deeper rivalries at play.
Mr. Wang was Mr. Ren’s political instructor in junior high school, and still “occasionally calls late at night” to chat, Mr. Ren wrote in a 2013 memoir.
But this time, Mr. Ren’s background offered no immunity.
The Cyberspace Administration office said he had broken the law by suggesting that the party and the people might not be inseparable, and it wiped out his microblog accounts. Party websites and newspapers heaped scorn on him, and party officials said he would face further punishment.
“Ren Zhiqiang represents a capitalist overturn-the-heavens faction,” said a commentary on Qianlong, a news website run by the Beijing city propaganda authorities.
Another commentary on the website hinted that Mr. Ren had the temerity to criticize Mr. Xi only because of Mr. Ren’s ties to Mr. Wang or other senior officials.
“We can’t help asking where a party member, who can ignore the party constitution, finds the gall to brazenly oppose the party,” it said. “This Ren Zhiqiang who likes to call leaders in the deep of the night, just who gave him the ‘courage’ to come forward and push over the wall?”
Mr. Ren has not commented publicly since he was criticized for his comments, and repeated calls to his cellphone were not answered.
The controversy does not suggest that Mr. Xi’s control is in danger; he remains powerful and popular with many Chinese people, who have welcomed his drive against graft.
But the authorities did not appear ready for the counteroffensive in support of Mr. Ren.
Several of his defenders said the episode had crystallized their fears that the exaltation of Mr. Xi and severe treatment of even mild dissent threatened to curtail the already limited room for debate. Some said that Mr. Ren’s vilification carried worrisome echoes of the “mass criticism” of the decade-long Cultural Revolution, which began in 1966.
And these concerns came not just from liberals outside the Communist Party.
Cai Xia, a professor at the Central Party School, the party’s main academy for training officials, wrote in an essay that Mr. Ren’s treatment “smacks of a political trial.”
“Controversy over different viewpoints is normal,” she wrote. “Cracking down on different opinions will bring severe dangers to the party.” The essay was later scrubbed from Chinese websites and condemned by a party newspaper.
Even in the National People’s Congress, the party-controlled legislature, hints of discontent emerged during an annual meeting that ended this week. Caixin, a Chinese magazine, quoted one member of a consultative council as saying, “Everyone is a bit dazed, and people don’t want to talk so much.”
The report was deleted from the magazine’s website, but Caixin posted an article in English chastising censors for cutting the “free speech comments.” That article was also removed from the website.
An editorial in late February in the newspaper of Mr. Wang’s anticorruption agency added to signs that some party officials were unhappy with Mr. Ren’s excoriation.
“Those who succeed in mighty undertakings are always open-minded and willing from the bottom of their hearts to hear different views,” the commentary said.
Mr. Ren’s connection with Mr. Wang has kindled speculation that the case is a sign of a higher-level power play. Was Mr. Wang sending a signal to Mr. Xi? Could the cracks of dissent exposed by Mr. Ren point to more destabilizing internal rifts?
No one outside the party’s inner circle knows, but if officials have held back from punishing Mr. Ren, his connections may explain why.
