Party Animals: my family and other CommunistsDAVID AARONOVITCH (JONATHAN CAPE, 304 PP, £17.99)Tablet bookshop price £16.20 • Tel 01420 592974 In 1956, two years after David Aaronovitch was born, the USSR invaded Hungary. The British Communist Party lost 20 per cent of its members, but not Aaronovitch’s parents, Sam and Lavender. They had already comfortably weathered all the impediments to continued loyalty that the Soviet Union had put in their way in the previous 40 or so years – the show trials, the Nazi-Soviet Pact, the Jewish doctors’ plot – and Soviet tanks rolling into Budapest to crush a popular uprising were not going to convince them that their god had  failed.Why did decent, intelligent, idealistic people, from labourers to intelle