This story is worth rehearsing, because it is part of who we are as a nation – or, at least, part of who we were until an eye-blink ago. Yes, we had our anti-Semites. But, almost uniquely in Europe, they never took over a major party – at least, not until Labour sank into the filthy sump of Corbynism, a degradation that repelled many Labour voters, disgusted at what had happened to the party of Hugh Dalton and Richard Crossman. We may not have thought of ourselves as an especially philo-Semitic nation, but our enemies certainly did. The European authoritarians...