In 2000, the then Chancellor of the Exchequer, Gordon Brown, accused Magdalen College, Oxford, of class bias in failing to admit a student called Laura Spence, a pupil at a Tyneside comprehensive. This was grossly unfair — how could the Chancellor know the details of a particular case? It was also outrageous in principle: why should a politician tell a university whom to admit? This Sunday, David Cameron did much the same thing.