President Xi is using the 75th anniversary of his regime to threaten Free China’s independence and stress what he sees as Communist China’s inevitable rise to global preeminence. It’s an apt moment to mark the mistakes that led to the stamping out of democracy on the mainland when Mao won China’s Civil War in 1949 — summed up then in America with the lament “Who Lost China?” — and to weigh the prospects for the future of self-rule on the mainland.