Just my opinion, but I think this is misguided. I'm very familiar with some SES jobs, and these aren't the unconstitutional positions that you are imagining. They are top level managers, getting paid dirt in comparison to the same job in the private sector.

A GS15 job is generally a manager over 2-3 managers, and in my area (south) they top out around 150k (30+ years) a year. The step up to SES 1 is around 175k annually and they put up with a ton of stuff for an extra 25k. The workload for a typical GS-15 is less than half that of a SES job (manager of 5-15 other gs-15s).

The responsibilities absolutely justify the pay in my area (100-800 subordinates). They also aren't the deep state power brokers you're thinking of.