Article I, Section 8, Clause 18:

[The Congress shall have Power . . . ] To make all Laws which shall be necessary and proper for carrying into Execution the foregoing Powers, and all other Powers vested by this Constitution in the Government of the United States, or in any Department or Officer thereof.

Congress’s power to conduct investigations stands on equal footing with its authority to legislate and appropriate. Although the „power of inquiry“ was not expressly provided for in the Constitution, it has nonetheless been acknowledged as „an essential and appropriate auxiliary to the legislative function“ derived implicitly from Article I’s vesting of „legislative Powers“ in the Congress. This implied constitutional prerogative to gather information related to legislative activity is both critical in purpose, as Congress „cannot legislate wisely or effectively in the absence of information,“ and extensive in scope, as Congress is empowered to obtain pertinent testimony and documents through investigations into nearly any matter. Included within the scope of the power is the authority to initiate investigations, hold hearings, gather testimony or documents from witnesses, and, in situations where either a government or private party is not forthcoming, compel compliance with congressional requests through the issuance and enforcement of subpoenas.