Auto workers are a pretty weird subspecies of the "middle class" though. As far as I can figure out, they're lower-class people with lower-class jobs who get upper-middle-class money.
If you can only get a high salary by joining a cartel, you are in a low-class job. If you join the cartel instead of earning what you're worth or finding a different line of work, you are a low-class person.
s/(firm|enterprise|organization)s?/people/g
In as much as UAW, for example, couldn't be considered a "firm" or an "enterprise" already. In some sense, UAW is a contracting firm whose service is its members' work product.
Whereas if GM tried firing all its union employees and hiring non-union labour instead... well, I'm sure you can guess what would happen.
If the UAW were a regular firm, it would be unobjectionable.