The events that led to Donald Trump’s election started in England in 1975. At a meeting a few months after Margaret Thatcher became leader of the Conservative party, one of her colleagues, or so the story goes, was explaining what he saw as the core beliefs of conservatism. She snapped open her handbag, pulled out a dog-eared book, and slammed it on the table. “This is what we believe,” she said. A political revolution that would sweep the world had begun.