Final answer:
The power to subpoena allows Congress to conduct hearings and investigations, compel evidence, and apply oversight of federal agencies. This authority is established through the Constitution, empowering Congress to ensure government accountability.
Step-by-step explanation:
The power to subpoena is a significant tool used by legislative bodies, such as Congress, to ensure compliance and gather evidence during investigations. This power enables the legislative body to require the presence of individuals to participate in hearings and to produce documents or other evidence that is relevant to the inquiry. Congress is particularly empowered to apply oversight of the federal bureaucracy due to its control over funding and the approval of presidential appointments. The U.S. House Oversight Committee, for example, uses its authority to enforce the efficiency, effectiveness, and accountability of the federal government and its agencies.
In situations where bureaucratic agencies are involved in significant errors or controversies, Congress can utilize hearings as an opportunity to investigate and demand accountability. These powers are rooted in several provisions of the U.S. Constitution, which state that Congress has the power 'to make all Laws which shall be necessary and proper for carrying into Execution the foregoing powers' and that it shall have the power to enforce legislation related to its constitutional mandates.