This is exactly right. It’s worth pointing out that some of the race riots of the late 19th Century occurred when black farmers/sharecroppers tried to negotiate better deals with white landowners. Free labor basically meant that poor whites had diminished labor prospects, thus presenting an ecological crisis. This was partly remedied by giving poorer whites jobs managing black slaves in different capacities.
When the system of slavery ended, that social class structure faced an instant crisis. Jim Crow was as much about restoring that structure in ways that the federal government would tolerate, and it was about making sure that working class whites didn’t rise up against upper class whites when capital and production inputs declined.
The Republicans, by virtue of things like the Southern Strategy, are the guardians of the Southern Democratic legacy. Republicans no longer try to compete on the battlefield of ideas - they’ve checked out. They know that they can’t win democratically, which means that they have to win undemocratically. They have to use the machinery of political power to their advantage and overpower democracy. And that’s precisely what they intend to do - and are doing right now.
In order to achieve that, though, they have to be solidly unified. Republicans don’t have the same levels of wealth, so they can’t really use economic status as a cause to rally around. It comes down to culture - more specifically, religion and race. They will use religion and race interchangeably, depending on their audience at any given moment. They’ll try to dress it up and tone it down somewhat while they still have to compete in elections, but as they get more sophisticated at rigging elections, they will become increasingly and viciously hostile toward non-whites.
Worse, we’re approaching a serious ecological crisis in the next 10-20 years. When an ecological crisis happens, there are two ways to respond. The powers that be can either reallocate capital, or they can reduce the ‘waste’ (unemployed and underutilized people) in an attempt to lower maintenance costs. I seriously doubt these guys would give even a thought to the first option, which leaves the second one.