In lots of reform-y areas, the issue is not predominantly that "immigrants are taking our jobs", but instead actually "the Tories closed down all our local industries and entrusted the recovery of our town to the supposed 'wisdom' of the free market, which didn't work and now there aren't many jobs". Yes, immigration hasn't helped, but even if the immigrants went away, a lot of the remaining jobs in these towns would be low paid, with minimal chance of technical progression.
Yes that's the thing really. Typically there are still jobs around (he says writing from Teesside) unemployment in Middlesbrough is apparently running at around 5.3% (which compares with the North East level of 5.1% and UK wide 4.5%) which isn't particularly terrible (seeing as in general an unemployment rate of 4% is considered healthy for an economy). So it's not as if we have great swathes of people listlessly lolling around on Universal Credit desperate for work.
But, the issue is, that much of that work is low paid and often precarious. Working in a shipyard or a steel mill wasn't exactly a barrel of laughs but it was often, comparatively, fairly well paid and fairly secure (until towards the end anyway). There are still well paid jobs around (someone is buying the nice big houses in places like Wynyard and driving the shiny big new Range Rovers!) but there's a bit almost underclass (not meant in a derogatory way) of people who are just stuck in dead end jobs with no real hope of ever being able to improve their lot in life because the only way to do that might be to completely uproot themselves and their family from Teesside and move to somewhere else in the UK.
Brutal reality is that that's not probably all that practical if your a cleaner on minimum wage bringing up a small family so stuck you are.
Then looking around you your local area seems to be getting worse by the day (more pot holes, more graffiti, less well cared for public spaces), you can't get a doctors appointment anymore, your mum is waiting nine months for a hip replacement (maybe you'll have to give up that job and become her carer?), and your son has ADHD which can't get diagnosed for four years.
Is it any wonder that you'll latch onto anything and anyone that tells you that they have a solution for your despair? Particularly when you've tried voting for either of the main parties and as far as you can see things have just gotten worse (just perhaps at varying paces depending on the shade of political party)?