On the eve of Mr. Xi's first meeting with Mr. Trump, who has shown little interest in the cause of democracy in China (or elsewhere), it is fair to ask whether it is not time, finally, to stop expecting that China will liberalize any time soon.

There are certainly plenty of reasons for pessimism. Beijing has placed ever tighter restrictions on the press, packed its jails with human-rights activists and suppressed even Hong Kong's limited experiment with "one country, two systems." In contrast to previous eras of reaction, recently won social and cultural freedoms remain intact for ordinary Chinese, but a far-reaching turn to democracy has become increasingly hard to imagine.

Still, some historical perspective is in order--not because Mr. Xi shows any signs of relenting in his oppressive agenda but because it would be a mistake to confuse the present reality with permanence. Democratic ideals have deep roots in modern Chinese history and have surfaced again and again over the past century. This legacy should serve to remind us that not all Chinese, even in the worst of times, have been resigned to a politics of one-party rule.

The idea that China would develop into a constitutional republic was first and most forcefully proposed at the beginning of the previous century by Sun Yat-sen, the so-called father of modern China. Sun had studied in Hawaii, converted to Christianity and become a medical doctor before starting his campaign against dynastic rule. When his republican government replaced the collapsed Qing Dynasty in 1912, he called for "three phases of national reconstruction," starting with a period of martial law, followed by an interlude of "political tutelage" and culminating in constitutionalism. "Without such a process," he insisted, "disorder will be unavoidable."

Sun's concerns about the difficulty of even starting to implant liberal democracy in China were quickly confirmed. His presidency lasted just 41 days as the country slid into the control of regional warlords. But Sun persisted, going on to establish the Nationalist Party, whose role in promoting democratic ideals in China proved to be long and tortuous.

But even amid the strife of the warlord era, the dream remained of a very different China. During the May Fourth Movement of 1919, thousands of students, intellectuals and workers took to the streets to protest Japan's grab of German concessions in China at the conclusion of World War I and to rally for "science and democracy." Hu Shih, a prominent intellectual of the movement who later became Chinese ambassador in Washington, wryly summed up the spirit of the era: "The only way to have democracy is to have democracy. Government is an art, and as such, it needs practice." His generation intended to overturn China's conservative and absolutist traditional culture so that, in the words of another activist, the Chinese people could rid themselves of the "4,000-year-old garbage can on our backs."

Throughout his own trying decades as president of the new Republic of China in the 1930s and '40s, Chiang Kai-shek, who succeeded Sun Yat-sen as the leader of the Nationalist Party, was no model of democratic practice, often suppressing opposition and basic civil liberties. In theory, however, he never wavered in his devotion to Sun's road map to constitutionalism, insisting that, after the necessary period of "tutelage," the Nationalist Party would "carry out its original purpose and return sovereign power to the people."

Such hopes were dashed in 1949, when Chiang and the Nationalists were driven to Taiwan by Mao after the Communist Party's triumph in the Chinese civil war. But Taiwan has been a vindication of the Nationalists' hopes. A process of liberalization began there in earnest in the mid-1980s with the lifting of martial law and a new tolerance for protests and opposition parties. Today, in the face of a newly autocratic and aggressive China, Taiwan remains a sturdy democracy.