In the 1970 case of Mayberry v. Pennsylvania, the U.S. Supreme Court ruled that a defendant cannot be tried for contempt by a judge who has been personally insulted or criticized by said defendant during trial proceedings. The case involved Fred Ewing Mayberry, who was convicted on several counts of robbery and related offenses in Pennsylvania state court. During his trial, he made derogatory remarks about the presiding judge which resulted in him being charged with criminal contempt of court. He was subsequently sentenced to an additional term of imprisonment for this offense without having another judge hear his contempt charges. The Supreme Court reversed this decision stating that due process requires a "cool and dispassionate" hearing when it comes to such matters - something not possible if conducted by a potentially biased party i.e., the offended judge himself/herself. Therefore, any personal attacks against judges must be dealt with separately from ongoing trials and should ideally involve different judicial officers to ensure impartiality.

In the dissenting opinion for Mayberry v. Pennsylvania, Justice Hugo Black argued that a defendant's right to self-representation should not be compromised due to disruptive behavior in court. He believed that the majority ruling allowed judges too much discretion in deciding when defendants forfeit their rights through misconduct. According to him, this could lead to arbitrary decisions and potential abuse of power by judges who might interpret any form of disagreement or resistance from defendants as disruptive behavior warranting forfeiture of their rights. Furthermore, he contended that if a defendant is deemed incapable of conducting his own defense due to mental illness or other reasons, then it would be more appropriate for the court-appointed counsel rather than another judge stepping in as was done in this case.