For several years Donald Trump has depicted himself as a kind of Roger Thornhill, the advertising executive in Alfred Hitchcock’s North by Northwest played by Cary Grant. Thornhill tells his secretary at the outset of the film that in his line of work there is no such thing as a lie only ‘expedient exaggeration’ and soon gets swept up in the machinations of the Cold War deep state as a gang of thugs mistakes him for someone named George Kaplan.