Photo by Topical Press Agency/Getty Images Winston Churchill was crowned the greatest Briton of all time by a BBC poll in 2002. According to a new survey by the think tank Policy Exchange, however, only one in five British people between 18 and 24 now have a positive view of the wartime leader; 58 per cent of over-65s, by contrast, view him positively. Overall, he gets the approval of just 36 per cent of the British public. Another poll from this year, by YouGov, offers a more encouraging picture for Churchill’s admirers, but even here the generational divide persists: 76...