Two standbys for Western liberals — Hannah Arendt’s “The Origins of Totalitarianism” and George Washington’s Farewell Address, which outlines his argument for term limits — have always sold well.

In the last several weeks, both works circulated on the Chinese internet, in a quiet protest against Mr. Xi’s decision to scrap the Chinese Constitution’s two-term limit for presidents. Most likely, the censors never read what Washington had to say, Mr. Liu said.

Weekends are the busiest time at the store, and on a recent Saturday the narrow aisles were packed, especially around the nonfiction shelves. Fiction is not the store’s strength.

There is plenty of Margaret Atwood and Alice Munro but no Joan Didion. Books on feminism merit only two shelves, a function of slow demand.

In the philosophy section, Sue Ping, 29, a Tsinghua University M.B.A. student dressed in a white sweater, jeans and a black beret, was searching for Plato’s “The Republic.” “For me, it’s paradise,” Ms. Ping said of the store. “I buy online but I come because I like the atmosphere. It’s very open, you feel welcome.”

A few shelves away, Daisy Fu, 45, a primary school science teacher, who came with her husband on their motorbike, was deciding whether to buy a book about North Korea. “A bookstore is a symbol of culture; we need it,” she said. “Even though I don’t come often, it’s important to know I can come and walk among the books.”

One book that Mr. Liu knows he will never be able to stock stands out. Works critical of Mao Zedong are automatically banned, and a sensational memoir, “A Life of Chairman Mao” by Li Zhisui, Mao’s personal doctor of many years, is considered a particular abomination. The book describes Mao as a tyrannical personality with a fiendish sexual appetite and appalling personal hygiene who suffered from a motor neuron disease in his last years.

“There is literally no way to get this book in China,” Mr. Liu said. “Just imagine if I put two copies on the shelves. The minimum punishment would be a fine of $3,000. The medium-level punishment would be shutting down the bookstore. And the most extreme would be the bookstore owner jailed for three to five years.”