When a political party is hit by a crisis, the tendency these days is for both the politicians and their supporters to pretend that there isn’t a crisis at all, hunker down inside a comfortable state of denial and blame it all on a hostile media. To a degree, this has always happened — but social media has unquestionably exacerbated the process, to the extent that at any one moment a vast number of people are living under a bizarre delusion from which only much later do they emerge blinking into the sunlight.