But in this "Elysium"-like scenario, that same class would have automated protection in place that makes them ~untouchable and capable of keeping the rest of humanity incapable of pushing back.
I don't believe this to be true. Sure, for a short period of time they may be "untouchable". Long term, nope. Most of them can't do anything for themselves in terms of real world skills at this point. They are, literally, the most vulnerable without the protection and production of others.
This. And unless people were not paying attention, the automated protection part is getting pretty close to reality.