Shanghai — Protesters pushed to the brink by China's strict COVID measures in Shanghai called for the removal of the country's all-powerful leader and clashed with police Sunday as crowds took to the streets in several cities in an astounding challenge to the government. Police forcibly cleared the demonstrators in China's financial capital who called for Xi Jinping's resignation and the end of the Chinese Communist Party's rule — but hours later people rallied again in the same spot, and social media reports indicated protests also spread to at least seven other cities, including the capital of Beijing, and dozens of university campuses. Largescale protests are exceedingly rare in China, where public expressions of dissent are routinely stifled — but a direct rebuke of Xi, the country's most powerful leader in decades, is extraordinary. Three years after the virus first emerged, China is the only major country still trying to stop transmission of COVID-19 — a "zero COVID" policy that