As an assassination attempt on US President Donald Trump, the unsuccessful bid by a suspect identified in US media as Cole Tomas Allen, from California, scarcely makes the grade. The alleged shooter failed to get past the checkpoints on the floor in the Washington Hilton above the cavernous hall where the White House correspondents’ dinner was taking place, with the President and his senior lieutenants in attendance. Perhaps the most important question about the attack will never be answered: what proportion of the American population would have given a silent sigh of relief if Trump had been assassinated? Some 63...