What's the reason for Labour's abysmal performance in these by-elections and their national polling? Is it simply the leadership of Jeremy Corbyn? Or are there more significant factors?
Corbyn is an extremely incompetent leader. From a policy perspective, he's also somewhat out of step with mainstream Britain, but that alone wouldn't necessarily be enough to cause Labour to lose seats like Copeland. The real problem is that Labour under his leadership has been an organizational disaster, flailing from one crisis to the next and blaming all of their problems on "Blairites," never mind that Tony Blair left office a full decade ago. Corbyn's supporters are worse than the man himself and focused on internal party score-settling against perceived enemies (mainly those evil center-leftist traitors) and purity rituals over any serious effort to win over voters, and Corbyn has demonstrated no interest whatsoever in trying to bring them to heel.
The first time I heard Jeremy Corbyn he was both going on about the importance of addressing global warming (fine) and that some coal mines in the U.K maybe should be re-opened (oh dear) and I wondered if his main concern was with settling scores with Margaret Thatcher from 30 years ago.