Brazil's Supreme Court is grappling with an unprecedented crisis marked by canceled sessions, conflicting judicial decisions, and allegations of corruption, political bias, and police interference among its members. These developments unfold as the nation approaches a presidential election in October, featuring incumbent Luiz Inácio Lula da Silva and Senator Flávio Bolsonaro, son of former President Jair Bolsonaro.

The current turmoil is largely linked to the collapse of Banco Master, a mid-sized bank with up to $16 billion in assets, which was shut down last November following an extensive investigation into a fraud scheme involving billions of reais. Several prominent politicians and members of the judiciary have been connected to the case.

Justice André Mendonça, appointed by former President Jair Bolsonaro, was initially overseeing the Banco Master case at the Supreme Court. The bank's former head, Daniel Vorcaro, was arrested this year, with investigations indicating business dealings with high-ranking politicians, including Senator Bolsonaro. Concurrently, Justice Alexandre de Moraes, a political rival of Mendonça, reportedly provided legal advice to Vorcaro. Documents related to the investigation also show that de Moraes' wife had a substantial contract to provide legal services to Banco Master.

Meanwhile, investigations into Senator Bolsonaro's relationship with Vorcaro and payments for a film about his father's life have progressed more slowly. Senator Bolsonaro has acknowledged receiving the payment but denies any wrongdoing.

Accusations of bias have surfaced, with some Supreme Court justices publicly alleging that Mendonça has selectively released case information and deliberately delayed investigations involving Senator Bolsonaro to influence the upcoming elections. Mendonça has denied these claims.

Reports indicate that Mendonca sought the suspension of de Moraes while the court deliberates on whether to investigate him for corruption. In response, de Moraes has filed a request for Mendonça to be investigated by the court and potentially impeached by the Senate for initiating an unauthorized proceeding against him.

The upcoming presidential election carries significant implications for the composition of the Supreme Court. Brazil's next president will appoint at least four new justices, who can serve until age 75. Some senators allied with Flávio Bolsonaro have pledged to advocate for the impeachment of Supreme Court members, while allies of Lula are considering imposing term limits.

Justice de Moraes is viewed as a key figure by many supporters of Lula, particularly for his role in overseeing the case that led to former President Bolsonaro's conviction for attempting a coup after his 2022 election defeat. De Moraes, in his dual capacity as a Supreme Court justice and head of Brazil's electoral court during the 2022 election, took measures to combat disinformation and protect the electoral process amid unfounded doubts cast by Bolsonaro on the electronic voting system.

Analysts suggest that de Moraes' potential downfall could embolden the Bolsonaros to question election results should they lose again. Justice Kassio Nunes Marques, appointed by Bolsonaro, currently heads Brazil's top electoral court.

At a large rally in São Paulo, Senator Bolsonaro directly linked Lula to de Moraes, stating, "Whoever votes for Lula votes for Alexandre de Moraes," and vowed to reform the court if elected. "Because it's an extremely polarized campaign, all that is negative for de Moraes is, immediately, positive for the Bolsonaro family," commented independent political consultant Thomas Traumann, highlighting the Supreme Court crisis as a central theme in the presidential campaign.

In an effort to de-escalate tensions, Chief Justice Luiz Edson Fachin has removed Mendonça from overseeing the Banco Master investigations and ordered the unsealing of all related documents, which became publicly available on Friday.