It’s not just Boris Johnson’s fundamental lack of plausibility that is the problem. At Thursday evening’s daily Downing Street press conference, he seemed to have totally lost the plot. After a few days of trying to do “serious face” he had reverted to his default end-of-the-pier-show act; the Archie Rice who could no longer even entertain himself. Back were all the familiar smirks, knowing nods and third-rate gags. He sounded tonally deaf, totally at odds with the mood of the nation. When the country wants a man of substance, we get a man of straw.