I don't think the racial divisions themselves were deliberately engineered by elites in the way you're suggesting. Politicians and corporate interests absolutely took advantage of those existing prejudices, amplified them, and weaponized them for their own ends, but they didn't invent them. The reality is that many white Americans didn't need to be "tricked" into opposing class solidarity - they already saw their racial status as something worth preserving. And while it's true that social conditioning plays a role in shaping beliefs, that doesn't absolve them of responsibility for examining those beliefs, questioning them, or making better choices.
I just can't accept the belief that they were passive recipients, rather than active participants. I've lived too long to believe that. Racism in America wasn't something the ruling class created to divide people; it was already a core part of the country's foundation. Institutional chattel slaver, segregation, redlining, and every other form of racial exclusion weren't just cynical tools of economic elites, they were actively supported by huge segments of the white population who saw racial hierarchy as natural and necessary. Politicians weaponized those beliefs, but they didn't have to work very hard to do so.
That's why I think the problem isn't just that the Democrats failed to push an emotionally compelling class-based narrative, it's that many white voters don't see their class interests as more important than maintaining racial and cultural distinctions. Even if the Democrats tried harder to sell a economic justice message, what happens when a significant number of voters still reject it because they view any policy that benefits Black people as a threat?
I do think that *we* should fight harder to counteract right-wing propaganda, but I feel that that's only part of the equation. The other part is reckoning with the fact that a large portion of the electorate just doesn't need propaganda to oppose true class solidarity because they already do so instinctively, because that's the country we live in.