who went before Congress.
https://www.quora.com/How-does-congress-have-the-power-to-subpoena
To understand this authority, one must consider that a conventional subpoena requesting discovery (usually testimony) or the production of documents or other physical evidence is usually issued by an attorney on behalf the court (in his capacity as an officer of the court) rather than directly by a judge or the court itself. However, such subpoenas, while they should not be ignored, can be challenged before the court itself (typical reasons include undue burden, lack of relevance, etc.). What gives the subpoena "teeth" however is that a court may hold a party in contempt of court if they do not successfully challenge or comply with a subpoena once issued.
It seems that Congress has always believed itself endowed with the authority to also hold people in contempt; in this case contempt of Congress. This authority was recognized by the US Supreme court in 1821 in Anderson V Dunn, and later formally added to the US criminal code in 1857.
Additionally, although not well known, Congress is the Sovereign authority of the District of Columbia (in the limited way that US States are technically legally sovereign). While it is true that Washington D.C. has a town council, and elected mayor, etc which were enacted by laws approved by Congress, Congress has the constitutional authority to override or veto any of their acts or decisions. Thus it has (mostly) the same sovereign authorities as say the State of NY. Further Section I, article 8 of the constitution authorizes Congress to "constitute tribunals inferior to the Supreme Court." Meaning that Congress can create courts (but they must be lower ranking in authority than the US Supreme Court). It has exercised this authority and created numerous US District Courts, including (unsurprisingly) one for the District of Columbia. Congress has, using this authority, enacted rules which allow for congressional committees and/or individual committee chairs to act as officers of the court, and therefore issue subpoenas which, due to the contempt of congress statutes, have teeth.
That said, however, there are some interesting differences between congressional subpoenas and the more conventional civil and criminal counterparts. Among these are:
1. More limited scope, per Wilkinson v US, the subpoena must be related to the committee's or sub-committee's area of authority, the subpoena must be for information/testimony relevant to the matter, and finally, the inquiry must serve a valid and legitimate legislative purpose.
2. Except for the standards above, courts will generally not hear motions to vacate or amend congressional subpoenas, as the article I, section 6 of the constitution states, in part, that Congress "for any Speech or Debate in either House, they shall not be questioned in any other Place." This includes courts, and has been interpreted to mean that congressional investigations and deliberations are beyond the scope of the court's authority to review.
3. Inherent (as opposed to statutory) Contempt of Congress is tried by Congress itself (not a court or heard by a jury), cannot be reviewed by courts, and convictions and punishments are not subject to Presidential pardons. This was upheld by the Supreme Court in Jurney v MacCracken. Although as a practical matter, Inherent Contempt has not been used in almost a century.
= new reply since forum marked as read
