JUDICIAL IMPARTIALITY AT THE SUPREME FEDERAL COURT: THE MASTER CASE—BETWEEN THE APPEARANCE OF PARTIALITY, LEGAL DISQUALIFICATION, AND GROUNDS FOR RECUSAL

Abstract

This article examines the constitutional, statutory and conventional standards governing judicial impartiality in the Brazilian Supreme Court, using the 2026 procedural developments of the so-called Master Case as a case study. The research question is whether and under what conditions references to judges in evidentiary material, a possible legal interest in the outcome, and the objective appearance of bias may affect a judge's continued participation in proceedings before the Court. The study is legal, theoretical and case-oriented, adopts a qualitative approach, has exploratory and descriptive objectives, and employs bibliographic, documentary and case-law research through a predominantly deductive method. The documentary corpus includes the Brazilian Constitution, the Codes of Civil and Criminal Procedure, the Supreme Court's Internal Rules, the American Convention on Human Rights, case law from the Brazilian Supreme Court, the Inter-American Court of Human Rights and the European Court of Human Rights, as well as official records of Petitions 16,662 and 16,704 consulted through September 24, 2026. The analysis shows that impartiality has subjective and objective dimensions and that the appearance of neutrality is part of due process. Yet the appearance doctrine does not replace the identification of the applicable procedural regime, nor does any reference to a judge automatically amount to disqualification or recusal. In the Master Case, institutional measures involving reassignment, plenary review and verification of personal circumstances illustrate the need to distinguish legally relevant interest, mere documentary reference and political controversy. The article concludes that judicial legitimacy requires verifiable standards, reasoned decisions and procedural safeguards, without anticipating guilt or presuming bias in the abstract.