This week, the British government banned Hasan Piker and Cenk Uygur, two leftwing US commentators with millions of followers, from entering the country on the grounds that their presence would not be “conducive to the public good”. It did not spell out what it meant by this very broad phrase, but Piker and Uygur have accused the government of denying them entry because of their prolific criticism of Israel. Some critics have accused the pair of antisemitism, which they deny.A lot has been written about the Piker-Uygur ban, and I don’t think I need to litigate everything they have ever...