Final answer:
Presidential power in the U.S. is largely conditional and depends on various circumstances, which makes the answer True. The President and Congress share power in foreign policy matters. The Necessary and Proper Clause has expanded, not limited, the powers of the national government, making False the correct answer regarding its effect on government power. The correct option is A.
Step-by-step explanation:
Presidential power in the United States is indeed largely conditional, meaning that the President's influence is often dependent on a variety of circumstances. True is the correct answer to whether a president's power depends largely on circumstances.
The President shares power with Congress when it comes to foreign policy, reflecting a balance of power envisioned by the framers of the Constitution. In this realm, neither the President is entirely in charge nor does the Congress hold all the power; it is a shared responsibility.
The Necessary and Proper Clause has had the effect of increasing, rather than limiting, the power of the national government, which makes False the correct answer for its supposed effect on limiting power.
Furthermore, while the Constitution outlines certain explicit powers for the presidency, there are also inherent powers which are not explicitly stated but are implied through the language of the Constitution. The Supreme Court can rule on these inherent powers, sometimes expanding and other times limiting the executive power.
Overall, a president's performance and legacy are influenced by varying circumstances such as election outcomes, support in Congress, and external events that may provide opportunities or limitations to the exercise of power. The growth in presidential power can also be attributed to the expansion of the United States and its governmental power, international stature, and developments in mass communication.