It’s possible you were thinking of the white working class, but if that’s what you meant, then you should have said so.
It's not that hard to spin things in a way that people unknowingly vote for the opposite of what they actually want or need.
If people are intentionally voting for the opposite of what they actually need, why is this a problem? Who's the arbiter of what the voters "need" anyway? The voters are responsible for determining what they need, and voting for it; if they can't do that, then they're getting what they deserve, right?
Basically, this comes down to an argument of democracy vs. authoritarianism. Should the voters get what they want or vote for, even if it's seemingly not in their best interest? Or should some other party decide what the citizens need and force it on them?
Yeah, but this is a good thing. The labor class is a very strong supporter of the political party that pushes policies which increase the income gap, and votes strongly against anyone who tries to change this or go back to the policies you're talking about. So they're getting exactly what they're voting for.