I know it is fashionable right now to say that the attacks by the Tories don’t work in the way they thought they would because young voters have never heard of the IRA, or it was a long time ago and “Jezza is a man of peace”, or they grew up blaming British foreign policy, or tuition fees are terrible (they’re not) – or something.

And then there is so much appalling footage of Corbyn supporting the IRA, or McDonnell lionising direct action, that it produces overload and the eyes glaze over.

Sometimes, though, you see a bit of footage from a few years back or read a quote and it still takes the breath away. Are those people – women voters who think May uncaring it is claimed, and millions of low-turnout youngsters – seemingly shifting to Corbyn and McDonnell seriously proposing to vote for this pair?

Here is footage of McDonnell talking about direct action and celebrating the “smashing up” of Millbank. You remember that day when a fire extinguisher was dropped off a roof and fires were lit.

McDonnell says:

“To see that momentum build up just showed the best of our movement. It showed you what there was out there in term of resources. It just needed the one small spark laid back in November before last of the students kicking the shit out of Milbank, and then that spark lighting all the combustible material that then brought people out… and that’s the best of our movement.”

He is celebrating violence, quite clearly. Good grief, the sheer contemptibility of revolutionaries and the odious older fantasists who get an illicit thrill out of challenging the rule of law and urging on the mob in pursuit of political ends.

Corbyn and McDonnell are so far removed from the decent Labour party they took over that it is frightening that millions of Britons cannot see it or see it and do not care. The party of John Smith, Barbara Castle, Jim Callaghan, Tony Blair, Gordon Brown, Ed Miliband, Ed Balls, Yvette Cooper and Liz Kendall is led by… by… this?

McDonnell is the man who wants to be the nation’s Chancellor of the Exchequer. In under a fortnight he wants to walk through the front door of that Treasury building that rioting students set about vandalising (along with the desecrated cenotaph and an office block full of terrified people).