Which of the following is NOT a constitutional power of the President?

The correct answer, declaring war, is not a constitutional power granted to the President. According to the U.S. Constitution, the power to declare war is vested in Congress, specifically outlined in Article I, Section 8. This section enumerates the powers of Congress and explicitly states that only Congress can declare war, emphasizing the system of checks and balances that delineates the authority between the legislative and executive branches.

In contrast, the President is constitutionally empowered to act as the Commander in Chief of the armed forces, which allows for military command and operations, thereby facilitating military action once Congress has declared war. The President also possesses the power to veto legislation, a significant check on Congress's ability to pass laws, and the authority to grant pardons, which can alleviate or set aside certain legal penalties for federal offenses. Collectively, these powers illustrate the various ways in which the President interacts with both domestic and military affairs, but declaring war remains distinctly within the purview of Congress.