The Constitution enumerates certain powers which are reserved to the federal goverment and other powers which are delegated to the state.
Those powers which are not explicitly related in the document to any of the goverment levels will automatically be reserved to and exercised by the supreme federal goverment.
Why would an absolute monarch focus his energy on controlling this class of people? Nobles tend to have some power and influence over common people so it would be easier for them to revolt and overthrow the ruler.
