A transactional exchange of political interests is perfectly rational. Keep in mind the GOP were losing before they put the sheets on.
Racism is perfectly beneficial for racists when it works.
There's some racism in it, but it's about a lot more than that. It's about being discarded by progress, our whole concept of ownership & work as virtue. Back in the late 70's, when the 99% share of wealth reached its zenith, there were a lot more inefficiencies that actually created jobs & inhibited profit taking at the top. The way goods & services are produced & distributed has become much, much more efficient because it takes a lot less people to get it done. Time was when economic growth buoyed working people's fortunes but that doesn't work very well when growth is even more automated. Walmart drove main street out of business & Amazon will try to do the same to them. There's not much there for people who work with their hands. There's not much in long wall coal mining, lights out manufacturing, automated warehousing or a lot of other things, either. If you don't own any of it, you likely won't make any money from it. Your services are not required.
Long haul truck drivers are next, and why not? No sick leave, pensions, workmen's comp. No inefficiency from having to let operators rest.