‘All political careers end in failure,’ said Enoch Powell. Maybe. But just occasionally our imperfect political system throws up someone whose impact on our way of life, for good or ill, outlives them. In a series of elegant essays, Vernon Bogdanor, professor of government at King’s College London, examines the careers of six politicians – three from left of centre, three from the right – who, in his view, changed the political weather of modern Britain.