BEIJING, China — President Xi Jinping of China, the most powerful Chinese leader in decades and the architect of a nascent personality cult, has embarked on a sweeping campaign to reshape China and restore its place among the world’s great powers. But the policies he has pursued — an aggressive foreign policy, sweeping crackdowns on corruption and dissent, and a tightening grip on the economy and society — are strikingly reminiscent of China’s tumultuous past under Mao Zedong, the founder of the Communist state. In recent years, Mr. Xi has invoked Mao’s image with increasing frequency, even comparing himself to him. And his philosophy of .