 Why does he need immunity at all? The answer is, again, the executive has to be able to function in the constitutional order. So as the Supreme Court writes under Justice Roberts, a president inclined to take one course of action based on the public interest may instead opt for another apprehensive that criminal penalties may be falling upon his departure from office. And if a former president's official acts are routinely subjected to scrutiny and criminal prosecutions, the independence of the executive branch might be significantly undermined. The framers design of the presidency did not envision such counterproductive or burdens on the vigor and energy of the executive.