01/21/2020
Executive privilege allows the president and high-level executive branch officials to keep certain communications private. US v Nixon, 1974 found “constitutional underpinnings“ for executive privilege. “Whatever the nature of the privilege of confidentiality of Presidential communications in the exercise of Article II powers, the privilege can be said to derive from the supremacy of each branch within its own assigned area of constitutional duties,” Nixon, id.
So calling of witness such as Bolton can be violation of executive privilege or immunity. However, these privileges are not without limits. There can be circumstances in which they do not apply. The President has a right and even a duty to protect the Office of President by exercising these privileges. There is much uncharted water in this area that would likely require a court decision.