Who has the power to declare war?

The Constitution grants Congress the authority to declare war, making it the correct answer. This power is outlined in Article I, Section 8 of the Constitution, which specifically states that Congress has the authority to declare war and to raise and support armies. This was established by the Founding Fathers to ensure that the decision to go to war would involve a deliberative process, rather than being left solely in the hands of a single individual.

While the President serves as the Commander-in-Chief of the armed forces and has significant power in military matters, the actual declaration of war remains a Congressional responsibility. The Senate, as part of Congress, does play a critical role in approving treaties and confirming military appointments, but it does not singularly hold the power to declare war. The Supreme Court does not have any direct authority regarding declarations of war; its role is to interpret the law and ensure that the Constitution is upheld.