Why should anyone listen to a media system that overwhelmingly endorsed Johnson in December 2019? They knew him well, and told people who didn't, that he was fit for high office. Meanwhile, they encouraged the idea that his only competitor was a racist.
In their desperation to head off mild social democracy the newspapers and the national broadcaster gave legitimacy to a gaggle of incompetents leavened with actual psychopaths. Cummings-Johnson is as much a product of the BBC and the Guardian as of Murdoch et al.
These people are in the business of maintaining plausible deniability; it's their job and they are good at it. But it is important to register the full extent of what they did, and are now trying to obscure.
