The ongoing crisis within Brazil's Supreme Federal Court (STF), particularly surrounding Justice Alexandre de Moraes, is expected to be a central theme of the September 7th demonstrations. The crisis intensified after Justice André Mendonça unsealed private messages between Moraes and Daniel Vorcaro, former owner of Banco Master, implicated in a $10 billion banking fraud case. This revelation has fueled calls for Moraes's impeachment and sparked a public dispute between the two justices, with Moraes accusing Mendonça of administrative impropriety and abuse of authority.

Flávio Bolsonaro, a presidential candidate, and his allies are using the Moraes-Vorcaro scandal to galvanize support for the September 7th protests. They aim to transform the demonstrations into a broader critique of the Lula government and the STF, with slogans like "Fora, Lula; fora, Moraes." The Bolsonaro campaign hopes a strong turnout will boost their electoral prospects, despite some concern among PL politicians about potential low attendance due to voter despondency and weather conditions. The impeachment of Moraes is a key objective, and they envision electing senators committed to this goal.

Opposition figures have widely criticized Moraes's actions, viewing his accusation against Mendonça as retaliation for revealing the messages. Senator Rogério Marinho, leader of the opposition in the Senate, accused Moraes of turning investigations into a tool for "personal power." Former governor Romeu Zema directly attacked Moraes, likening him to a dictator. President Lula, while generally allied with the STF, has distanced himself from the immediate crisis, calling for a thorough investigation into the Master Bank case and judicial reforms, underscoring the political sensitivity of the situation.

The timing of these revelations, just before the September 7th protests, has amplified their political impact, pushing the future of the STF to the forefront of the upcoming elections. The outcome of these events, including the senatorial elections next month, could significantly alter the balance of power within the court, potentially leading to Moraes's impeachment and ushering in a new, more turbulent era for the STF.