On Sunday, Representative Alexandria Ocasio-Cortez made two striking remarks that seem related. First, she barely demurred when ABC News asked whether she aspired to run for president. “I haven’t ruled out the possibility,” she eventually said. Second, she tried to laugh off stances that progressives in her wing of the Democratic Party had taken in the preceding years: “‘Woke 1 was crazy,’” she said, echoing a comment that one of her allies had made about the heyday of ideas such as “defund the police.” Ocasio-Cortez represents an extremely liberal congressional district in New York City. The fact that she is...