It's all so familiar, this branding of anyone vaguely to the left of whoever UK's equivalent of Joe Lieberman is as being silly and childish.
As Jones suggests, the truth is that all the more Blairite New Labour people need to do is embrace the genuinely good things that Labour did while they were in government. But since they decided not to battle the Tory "ZOMG LABOUR SPENT ALL THE MONEYS" narrative, they can't do that. At least Miliband could muster up the "not quite as evil as the other guys" narrative reasonably well. Post-Miliband, Labour can't even manage that. As useless as a marzipan dildo.
