Final answer:
The most difficult presidential appointees for the president to control are Supreme Court justices.
Step-by-step explanation:
The most difficult presidential appointees for the president to control are Supreme Court justices.
Although cabinet members, ambassadors, and White House staff are all appointed by the president, Supreme Court justices serve for life and are not directly answerable to the president. They are nominated by the president and confirmed by the Senate, but once appointed, they have a high degree of independence and autonomy in their decision-making.
This lack of control over the actions and decisions of Supreme Court justices make them the most difficult appointees for the president to control.