Inherent contempt is the oldest of Congress's contempt powers, rooted in English parliamentary precedent and recognized by the Supreme Court in Anderson v. Dunn (1821). Under this power, Congress can direct its sergeant-at-arms to arrest a defiant witness, bring them before the full chamber for trial, and impose fines or imprisonment without filing charges in federal court. This mechanism does not depend on presidential cooperation or DOJ enforcement. The Senate last used inherent contempt in 1934. Neither chamber has used it since. Legal scholars have debated whether inherent contempt could be revived to counter executive branch refusals to cooperate with congressional investigations, though no modern Congress has attempted it.