Article I, Section 1:
All legislative Powers herein granted shall be vested in a Congress of the United States, which shall consist of a Senate and House of Representatives.
Beginning with the resolution adopted by the House of Representatives in 1827, which vested its Committee on Manufactures
with the power to send for persons and papers with a view to ascertain and report to this House in relation to a revision of the tariff duties on imported goods, 1 the two Houses have asserted the right to collect information from private persons as well as from governmental agencies when necessary to enlighten their judgment on proposed legislation. The first case to review the assertion saw a narrow view of the power taken and the Court held that the purpose of the inquiry was to pry improperly into private affairs without any possibility of legislating on the basis of what might be learned and further that the inquiry overstepped the bounds of legislative jurisdiction and invaded the provinces of the judiciary. 2
Subsequent cases, however, have given Congress the benefit of a presumption that its object is legitimate and related to the possible enactment of legislation. Shortly after Kilbourn, the Court declared that
it was certainly not necessary that the resolution should declare in advance what the Senate meditated doing when the investigation was concluded in order that the inquiry be under a lawful exercise of power. 3 Similarly, in McGrain v. Daugherty, 4 the investigation was presumed to have been undertaken in good faith to aid the Senate in legislating. Then, in Sinclair v. United States, 5 on its facts presenting a close parallel to Kilbourn, the Court affirmed the right of the Senate to carry out investigations of fraudulent leases of government property after suit for recovery had been instituted. The president of the lessee corporation had refused to testify on the ground that the questions related to his private affairs and to matters cognizable only in the courts wherein they were pending, asserting that the inquiry was not actually in aid of legislation. The Senate had prudently directed the investigating committee to ascertain what, if any, legislation might be advisable. Conceding
that Congress is without authority to compel disclosures for the purpose of aiding the prosecution of pending suits, the Court declared that the authority
to require pertinent disclosures in aid of its own constitutional power is not abridged because the information sought to be elicited may also be of use in such suits. 6
Although Sinclair and McGrain involved inquiries into the activities and dealings of private persons, these activities and dealings were in connection with property belonging to the United States Government, so that it could hardly be said that the inquiries concerned the merely personal or private affairs of any individual. 7 But, where the business, and the conduct of individuals are subject to congressional regulation, there exists the power of inquiry, 8 and in practice the areas of any individual's life immune from inquiry are probably fairly limited.
In the decade following World War II, there appeared a new kind of congressional inquiry unknown in prior periods of American history. Principally this was the result of the various investigations into the threat of subversion of the United States Government, but other subjects of congressional interest also contributed to the changed scene. This new phase of legislative inquiry involved a broad-scale intrusion into the lives and affairs of private citizens. 9 Because Congress clearly has the power to legislate to protect the nation and its citizens from subversion, espionage, and sedition, 10 it also has the power to inquire into the existence of the dangers of domestic or foreign-based subversive activities in many areas of American life, including education, 11 labor and industry, 12 and political activity. 13 Because its powers to regulate interstate commerce afford Congress the power to regulate corruption in labor-management relations, congressional committees may inquire into the extent of corruption in labor unions. 14 Because of its powers to legislate to protect the civil rights of its citizens, Congress may investigate organizations which allegedly act to deny those civil rights. 15 It is difficult in fact to conceive of areas into which congressional inquiry might not be carried, which is not the same, of course, as saying that the exercise of the power is unlimited.
One limitation on the power of inquiry that the cases have discussed concerns the contention that congressional investigations often have no legislative purpose but rather are aimed at achieving results through
exposure of disapproved persons and activities:
We have no doubt, wrote Chief Justice Warren,
that there is no congressional power to expose for the sake of exposure. 16 Although some Justices, always in dissent, have attempted to assert limitations in practice based upon this concept, the majority of Justices have adhered to the traditional precept that courts will not inquire into legislators' motives but will look 17 only to the question of power. 18
So long as Congress acts in pursuance of its constitutional power, the Judiciary lacks authority to intervene on the basis of the motives which spurred the exercise of that power. 19