As the Labour Party deserts its job and its responsibilities to play Cowboys and Indians it's worth while pointing out that both sides are right, though it's not clear whether one is crazier than the other and their combined efforts are making the party unelectable. People tend to like a party to be an alternative government to a civil war on wheels.
The gulf between the two camps is about how to get elected. The Blairites, who started sulking before Jeremy was elected, believe in Tony's approach which was to take Labour's core working class support for granted, give it nice smiles and warm words and not much else and make the party attractive to groups like the aspires, whoever they are, the south, the middle class or business or the lot by pulling Labour's teeth and pretending that it was the Liberal Party reincarnated.
The Corbyn lefty approach was older and argued that Labour had to be radical and left to build the working class vote because proletarians are in a majority and only need to be radicalised to bring them out in great numbers to bring victory and another 1945.
Tony's approach won in l997 (though given the Tory mess Michael Foot would have made it too). His government didn't deliver much to the workers:minimum wage and Sure Starts but no extra powers for the Trade Unions and lots of deregulation for the bankers and financiers who became more important to the government than the TUC, until they greedily screwed up everything with the recession.
The Corbyn approach represents a rank and file reaction against this. The benefits are that Corbyn himself is a sincere man of principle and that's more saleable than the plasticscene politicians who'll bend to any shape. People prefer a leader with values. Plus the fact that McDonnell is looking for serious answers to the serious question about the economy such as investment, inequality, higher taxes all the things no-one else dare tackle.
The weakness of the Corbyinites is that he doesn't look like a leader and he's boring. The weakness of the Blairites is that they've got too many jostling and inflated egos, too few ideas and no guts at all. No need to take either side but every need to force them to work together. If they don't, Labour's not only destroyed but useless as the only political instrument for advancing the cause of people which used to be its job in my time. Less sound of battle please and more the dull banging of heads being knocked together.