The U.S. Supreme Court case Liteky v. United States in 1993 revolved around the interpretation of a federal statute regarding judicial recusal, or when judges must disqualify themselves from a case due to potential bias or conflict of interest. The appellants, John Patrick Liteky and others were convicted for protesting inside the Supreme Court building and requested that their trial judge be disqualified on grounds of alleged bias against them based on his actions during previous trials involving similar protests. They argued that these past interactions constituted "extrajudicial" sources of bias under section 455(a) which requires judges to recuse themselves whenever they have “personal knowledge” about disputed evidentiary facts concerning proceedings; however, this was rejected by lower courts. In an unanimous decision written by Justice Antonin Scalia, the Supreme Court upheld those decisions stating that not all unfavorable disposition towards litigants demonstrates bias or partiality as required for recusal under section 455(a). It clarified that only extrajudicial sources could lead to such mandatory disqualification and further explained what constitutes an 'extrajudicial source'. In this context it meant something not introduced into proceedings by parties but originating outside them - personal biases stemming from background experiences unrelated to cases at hand.

In the dissenting opinion for Liteky v. United States, Justice Scalia argued that a judge's opinions formed during the course of current proceedings do not constitute grounds for recusal unless they display a deep-seated favoritism or antagonism that would make fair judgment impossible. He disagreed with the majority’s interpretation of “extrajudicial source” factor in determining bias or prejudice, stating it was unnecessary to limit its application only to sources outside judicial proceedings. Instead, he believed any bias should be considered regardless of its origin if it is strong enough to potentially affect impartiality. Furthermore, he contended that this ruling could lead judges to avoid forming definitive views on matters before them until late in their deliberations out of fear they may have to recuse themselves otherwise.