It’s often said that anti-Semitism is a shape-shifter, seen best in the way that the right-wing have painted the Jews as rootless revolutionaries and the left-wing have portrayed them as rapacious capitalists. It’s also grimly notable that – unlike prejudice against many other ethnic groups – it’s been equally appealing to the young and the old, the over-privileged and the under-privileged, the educated and the uneducated.