“They wanted to make an example of him, to scare anyone who might question what they do in the name of security,” Zhang’s wife, Li Aijie, told The Associated Press earlier this week, one day after she arrived in the United States and asked for political asylum. “Even someone who knows nothing about law would know that his punishment made no sense.”

Elsewhere in China, Zhang would have been sentenced to no more than three years, said his lawyer, Li Dunyong, and may not have been prosecuted at all.

But Xinjiang, the tense northwestern region where most Uighurs live, has been enveloped in recent years in a vast dragnet of Police Surveillance, which authorities insist is needed to root out separatism and Islamic extremism. Zhang, who moved to Xinjiang from central Henan province more than a decade ago in search of work, wondered in his social media posts whether these policies were stoking resentment among Uighurs. He warned that China’s restrictions on the Uighurs’ religious practices risked sparking an insurgency.

But questioning government policies in Xinjiang has become an untouchable third rail in today’s China.

Court records say Zhang was convicted of sending 274 posts from 2010 to 2015 on Twitter and the Chinese social media service WeChat that “resisted, attacked and smeared” the Communist Party and its policies, earning him 15 years in prison for inciting subversion of state power. He was given another five years for talking to foreign reporters and providing photos of the intense police presence in the streets of Xinjiang. That, the court said, amounted to providing intelligence about China’s anti-terror efforts to foreign organizations.

The court said it would combine the two punishments and sentence him to 19 years in prison.

He was convicted in January 2016. An appeals court in December 2016 refused to hear his petition, noting he had never expressed regret or admitted guilt.

Hoping to draw attention to Zhang’s plight, Li provided her husband’s court documents and letters from jail to the AP, as well as her own account.

The daughter of a farming family in Henan’s hardscrabble hill country, Li met Zhang in 2011 after stumbling across a personal ad he had arranged to have placed in a local park where singles sought partners. The flier said he sold wireless routers and listed his modest height: 168 centimeters (5-foot-6). On their first date, when Zhang was back home in Henan, he wore a jacket with threadbare cuffs but showed Li his identity card in an awkward attempt to prove he was genuine.

That simple directness was something she grew to love, Li said, but it was also Zhang’s downfall. He had been repeatedly warned by police about his social media activity, but he always ignored them.

When the authorities finally arrested him in 2015, they told Li he was suspected of inciting ethnic hatred. The charges were raised to subversion and espionage, Li suspects, after he refused to confess. In a letter he wrote to Li and his sister earlier this year, Zhang described how Nelson Mandela, who spent nearly three decades in prison, had become an inspiration.

“Life must have greater meaning beyond the material. Our mouths are not just for eating, but also for speaking out,” Zhang wrote.

While the severity of Zhang’s sentence stands out, others in the region have been punished for mild criticism.

Ma Like, a Muslim hostel owner in the ancient Silk Road city of Kashgar, was accused in April of “propagating extremism” because he had retweeted two Weibo posts — one about how Chinese policies were alienating Uighurs, the other a veiled reference to restrictions on the Islamic headdress — according to two of Ma’s friends, who provided copies of Ma’s indictment and spoke on condition of anonymity for fear of government retaliation.

Wang Lixiong, a Han Chinese writer and dissident, said that when it comes to Xinjiang, even calls for dialogue can result in imprisonment.

“The government removes the middle road so it leaves two extremes,” Wang said. “You’re either their mortal enemy or their slave.”

Zhang was arrested when Li was three months pregnant. She gave birth to their son two years ago, while he was being held in a desert prison. She returned home to Henan to raise him and began blogging and speaking to the overseas media.

The authorities tried to silence Li, pounding on her front door as she did a phone interview, for example, and threatening to derail the careers of her two brothers, low-level government workers.

Li’s family begged her to divorce Zhang, even give up their child.

When words didn’t sway her, in October her siblings and parents beat her, leaving her bruised on the family home’s floor.

“I cannot hate them,” Li said. “They were trying to resist enormous pressure. But after that, I had nowhere to go.”

A month ago, she sneaked away and made her way to Bangkok. With the help of U.S. aid organizations, she flew to Texas, where a host family had been found for her, and where she hopes to start a new life with her son.

When she files her asylum paperwork, she lists the boy’s legal name.

But in quiet moments, she calls him by his nickname: Xiao Man De La.

“Little Mandela.”