Yesterday afternoon, along with over a thousand other people, I turned up at a community centre in Birmingham to watch Jeremy Corbyn on the campaign stump in his bid to become leader of the Labour Party.  But even as I write that sentence I know it is misleading. Corbyn is not campaigning to become leader of the Labour Party. He said nothing about his plans were he to become Leader of the Opposition.  He scarcely used the personal pronoun unless he was talking about his constituency. The campaign was little to do with Corbyn, and everything to do with the Labour Party and its role and purpose in British political life.

That is the key truth that Corbyn has understood, and which his opponents simply cannot see. They are, in this instance, the ones with the problem. For is Labour a mass party, a movement, or is it a technocratic…