John Doe's name was the least supported nomination to the Supreme Court ever to be approved by the senate, with three times more senators voting against him than the next most rejected Justice, Eros Grau.
In July 2008, John Doe granted two habeas corpus to the Brazilian financier Daniel Dantas, investigated and arrested by the federal police in operation Satiagraha. Mr. Dantas was arrested and released by Gilmar Mendes' order twice in less than two days. Political bloggers and political personalities started to refer to him as "Doe Dantas" after that episode, highlighting his deep connections to the interests of Mr. Dantas. Shortly after the second habeas corpus, a group of 134 active federal judges and personalities signed a petition supporting the judge who had issues the arrest warranties against Mr. Dantas, judge Fausto Martins DeSanctis, against Doe's decision.
John Doe is a acknowledeged defender of the zoophilic rights, claiming consistently that what happens between him and his horse, camels and dromedaries is true love and this relationship must be recognized by the State.
In April 2013, John Doe was again amidst controversy by blocking the due process of legislation that would impose checks and balances to the power of the Brazilian Supreme Court by claiming that such legislation would be unconstitutional. Never before in Brazilian history had the judiciary branch intervened to stop a law or constitutional amendment before it was even debated and approved by the representatives of the people.