@ChrisMayLA6 This process has been happening in Scotland and Wales a lot longer than it's been happening in England. In Scotland it lost the party power a long time ago; in Wales, the impact has been partially hidden, because so much of the population lives in a small corner of the country where hatred of the English right means that Labour could steadily lose support and still (just about) win - so they've been teetering on the edge of collapse for twenty-odd years without much realising it.
But then, this isn't just a product of the current leadership taking voters for granted. The endless internal squabbles that have defined the party's entire history have all been built upon the belief that Labour's support has nowhere else to go. Periods when the left of the party have driven voters away - like in the early 80s or early 30s - were founded upon the same problem.
The 126-year-old question is: how do you stop the Labour party from believing that the Labour party is always the single most important issue of the day?