So, I am heading to bed for the night, because I have been awake all night and day and the day before to catch the debate - but the short answer is: The decline of the middle class and the petite burgeoisie - which I in this case view not in the traditional definition, but also broader, as all the people owning a little bit of capital i.e. savings for old age in some fond or maybe a house of their own. Also the disappearance of job security and stable work relations.
With it, the conservative “lets keep things as they were” mindset of people who had a decent enough life, i.e. mostly boomers that lived through the economic growth phase of the post-war era, but also younger people dreaming of that time or having profited from it through their parents, comes into crisis. But as this mindset argues from its own experience, it dreams of the past (“Things worked back then, right?”), while missing, that the very same “working” system was what had within it, already the inherent nature that eventually led to it decaying around us. So they need to explain the decline as something caused by an outsider, a malevolent force.
At the same time, this decline of the middle class leads them to try and grasp to divisions that might “save” them from proletarisation - becoming properly dependend on paycheck to paycheck and owning nothing but their own labour power to sell on the market. So, racism for example - if you are white, you might just be spared from the above fate. And you can kick down, targeting all those brown people below instead of punching up - the latter is a lot more risky after all. And the people up above can’t be at fault, after all, you (or the people you heard about from the past) had a great life when those were around, right? It just have to be the “right” people, like you and the people of your nationality/race/religion/other ingroup - often depressingly arbitrary.
This is still a very reductive summary, a lot is missing, globalisation, how it relates to the net rate of profit, how consolidation happens, details about the ideology of our current times. But broken down to it’s basics it can be summarised as such. The middle class is disappearing as a consequence of capitalist development, which leads to them becoming panicky and diving headfirst into ideology.
Well, anyway, good night, hope it was possible to understand what I was trying to bring across in my rambling