The enactment of the VWPA and the amendment of 18 U.S. Code section 1503 expanded and strengthened existing protections aimed at achieving the dual goals of protecting witnesses in Federal proceedings and maintaining the integrity of the judicial process. Although intended to provide a prohibition against intimidation of witnesses, the VWPA has instead engendered judicial disagreement as to the scope of the amended omnibus obstruction statute and the constitutional limits of affirmative defenses. Section 1503 makes it unlawful for a person to corruptly influence, obstruct, impede or endeavor to influence, obstruct, or impede the due administration of justice. To obtain a conviction under this section, the government is required to prove that there was a pending Federal judicial proceeding, that the defendant knew of the proceeding, and that the defendant intentionally interfered with or attempted to interfere with it. In discussing provisions pertinent to the obstruction of justice, defenses are also outlined. The review of witness-tampering provisions discusses history, constitutionality, intended scope, venue for prosecution, and elements of the offense. 174 footnotes