Pedro Ernesto Baptista
Pedro Ernesto Baptista, or Pedro Ernesto as he would later be known, was a successful medical surgeon who became mayor of Rio de Janeiro in mid-1931. His two terms were from September 30, 1931 until October 2, 1934; and from April 7, 1935 until April 4, 1936.
He would later be known as the first Populist Brazilian politician. His victory in the elections for mayor was partly due to the backing of then-president of Brazil, Getúlio Vargas. During his term in office, he made several social and populist reforms in the fields of health care, education, and indigenous culture (to his credit stands the revival of the Samba).
He quickly became the most popular politician in Brazil, and was even considered as a suitable candidate for the future presidential elections of 1938.
In 1936, however, Ernesto was charged with participation in a communist conspiracy against the government, and was arrested. He spent the next few years defending himself against charges of treason, and was eventually absolved. By then, however, Vargas had already launched his autocratic "New State" (Estado Novo), erasing the possibility of democratic elections.
References
Michael L. Conniff, “Brazil’s Populist Republic and Beyond”, in Conniff (ed.), Populism in Latin America