When Donald Trump calls someone a socialist he is not using the word in the same way that, say, Zohran Mamdani does. The mayor of New York espouses democratic socialism as a mission of equitable distribution of wealth and opportunity. The US president says socialism only pretends to be democratic “because it sounds so nice”; that “it’s really communism you’re talking about” and that people such as Mamdani pose “the biggest threat to our nation … since its founding”.People who despise an idea, seeing it as the manifestation of everything wicked, cannot be expected to define it accurately. As with...