Policy, rhetoric and public bewilderment - The Cloud of Unknowing

Why does so much of contemporary politics feel divisive and unproductive?  Why is public understanding and engagement in the issues of the day so low?  Some blame political opponents. For many others it’s the media – from Fox News to the BBC.  Still others wonder whether it's because the public's own attention span is on the wane.
In "The Cloud of Unknowing" Mark Thompson, the outgoing Director-General of the BBC, searches for an explanation by looking instead at our public language.  He argues that - for reasons which go far beyond politics or partisan blame - it is undergoing profound change, becoming increasingly optimised for political differentiation and advantage to the detriment of rhetoric's other fundamental role in a democracy - which is to enable ordinary citizens to understand and therefore participate in the great policy questions of the day.
If that link is broken and policy becomes the preserve of a technocratic elite, the health of democracy itself is threatened.