This paper aims at presenting, by the analyzes of actual cases and the study of the historical evolution of Brazilian constitutions, the ways the controversial disputes around the legal instrument known as privileged jurisdiction due to public function prerogatives impact the Brazilian Supreme Court (STF) participation in the country s democratic political process. The public has usually related this constitutional safeguard to impunity and incentive to corruption, which has been summarized over the years by the popular usage of the non-technical, shortened term privileged jurisdiction (foro privilegiado). However, it is possible to acknowledge it as an important tool for the essential protection of elected mandates. Designed to be an obstacle to the persecution of political authorities, the instrument is also intended to avoid authorities misuse of their rights against Justice. The absence of easy solutions for criminal processual dilemmas related to the jurisdictional treatment of criminal matters concerning political authorities is a fact. It is no coincidence there are various examples of original and special solutions dealing with the matter throughout Latin America as well as in other global powers. The time frame of the study presents criminal procedures recently tried or in process at the Federal Supreme Court. These court actions allow us to notice the oscillation in the Court’s interpretation of the rules of the legal instrument which in turn allows less certainty and predictability concerning the delicate criminal accusations against political authorities in the country. This uncertainty, which is encouraged by the Court s decisions, ends up establishing a significant level of insecurity for the democratic regime in Brazil. That could be easily avoided by the setting of a more objective constitutional rule for the subject and by the ceasing of STF’s repetitive attempts to reform constitutional ruling or other legislation by means of expanded interpretations on the matter. The most recent decision on the subject by STF is found in the Question of Order in Criminal Procedure 937, which brought changes for the ruling of the matter. In the author s opinion, the changes reached their goal of lowering the number of cases reaching the Supreme Court, more accordingly with its original competence, however, they did not clarify important issues so as to guarantee consensus about their interpretation.