Oh, yep. I'd include the Cabinet as well. Not the heads of agencies, though. I view those like corporate CEOs. Influential as all get out, but not really nobility.
See I view them EXACTLY like nobility. The people getting these positions expend considerable resources and money to be "appointed" with the title they seek. Why, because of the prestige and massive side benefits that the position holds - AKA nobility. But again pretty far afield.