Brazil's first black Supreme Court justice says he won't run for president, quashing widespread speculation.

Joaquim Barbosa announced his decision on Twitter Tuesday, calling it "strictly personal."

Many thought Barbosa could win support from voters on the left and right and unify a deeply divided Brazil. Barbosa has voiced support for social programs identified with the left but also won praise from conservatives for handing down corruption convictions to members of former President Luiz Inacio Lula da Silva's leftist administration.

Da Silva is now in jail on his own corruption conviction. He leads presidential preference polls even though it's unlikely he will be able to run. In second place is far-right congressman Jair Bolsonaro.

A recent poll showed Barbosa gaining support for the October vote, but still in single digits.