For some of the protesters, democracy is a matter of principle. Others, like middle-class people across mainland China, are worried about housing, education and their own job prospects. They want representation because they are unhappy with how they are governed. Whatever their motivation, the protests present a troubling challenge for the Communist Party. They are reminiscent not just of uprisings that have toppled dictators in recent years from Cairo to Kiev, but also of the student protests in Tiananmen Square 25 years ago. The decision to shoot those protesters succeeded in restoring order, but generated mistrust that still pervades the world’s dealings with China, and China’s with its own citizens.