Opinion of the Justices

*531The following answer was returned:

To the Honorable Senate:

That Congress and State Legislatures have broad and extensive powers of investigation is no longer open to serious doubt. While it was questioned at one time whether Congress could act as the grand inquest of the hation (Kilbourn v. Thompson, 103 U. S. 168) that view is not now law. McGrain v. Daugherty, 273 U. S. 135; Sinclair v. United States, 279 U. S. 263; Jurney v. MacCracken, 294 U. S. 125. In order to legislate it is necessary to be informed and investigation is usually a prerequisite to adequate information. The same thought in…