I was thinking about all the jokey "we should be 20 points ahead, resign immediately" replies to those recent opinion polls. To a casual observer that must look like Starmer is doing atrociously, which if kept up quite plausibly slowly percolates through society. There is some...
psephological evidence that a a significant number of people vote according to who they think will win. So, basically, the anti-Corbyn scorched earth policy has created a series of memes that could make any leader unelectable until we stop finding them funny (in approx 25 years).