Contempt of Congress[1] is the misdemeanor act of obstructing the work of the United States Congress or one of its committees. Historically, the bribery of a U.S. senator or U.S. representative was considered contempt of Congress. In modern times, contempt of Congress has generally applied to the refusal to comply with a subpoena issued by a congressional committee or subcommittee—usually seeking to compel either testimony or the production of requested documents.[2]
Obstruction of justice is the impediment of governmental activities. There are a host of federal criminal laws that prohibit obstructions of justice. The six most general outlaw obstruction of judicial proceedings (18 U.S.C. 1503), witness tampering (18 U.S.C. 1512), witness retaliation (18 U.S.C. 1513), obstruction of congressional or administrative proceedings (18 U.S.C. 1505), conspiracy to defraud the United States (18 U.S.C. 371), and contempt (a creature of statute, rule and common law). All but Section 1503 cover congressional activities.