I'm afraid Hattersley's day, and argument are long gone. As have the rationale of some of the posters on here.
As I posted last night, (I think on one of the anti-Corbyn threads) one commentator was saying that the right of the LP just do not understand the democracy of a Labour Party that now has such a large number of members who don't agree with them. They - Hattersley is an example - are obsessed with destroying the left of their own party and, in the process, do not care if they destroy the party altogether. We see it on here where those who constantly attack the current leadership and thinking are usually only supported by right-wing Tories but they still cannot see the damage they are doing to 'their' Labour Party.
Of course no party belongs to any one person or small group. They could be positive about their views and grow the number in the party who agree with them. Get out there and recruit so that their opinion is heard. They do not seem to understand that you recruit from the positive not the negative - that just turns people away. What happens, sadly, is sniping from the side. We see politicians who could have had a place in the party, brought their views to bear, and had an influence, but it seems as if they feel that if they can't be top-dog, overriding the democratic process, then all they can do is make the sly and petty attacks we have seen and whinge that the party they changed is changing again.