In October 3rd 1955, centrist candidate Juscelino Kubitschek (JK) was elected president of Brazil. He had 36% of the vote and he defeated right-wing candidates Juarez Távora, Ademar de Barros and Plínio Salgado (
https://sites.google.com/site/atlaseleicoespresidenciais/eleio-de-1955). JK was supported by the left and his running mate, the leftist João Goulart, was elected vice president (there were different elections).
The famous right-wing journalist and politician Carlos Lacerda disliked the result and considered that JK's victory was not legitimate because he didn't have >50% (althouth the constitution of 1946 accepted plurality) and because JK won only because the communists voted for him and the communist party was banned in 1947 (yes, he used this argument!). Some far-right generals started to organize a plot, in order to avoid JK's inauguration. But there was a powerful general who was loyal to the constitution: Henrique Lott. He moved his troops and avoided the coup.
The sitting lame duck president was the right-wing Café Filho. He was the vice-president and he became president after the suicide of center-left president Getúlio Vargas in August 1954 (in other thread I explain how they were in the same ticket in the 1950 election). Café Filho supported the plot. When the plot failed, the Congress impeached him. President of Senate Nereu Ramos became the acting president until JK's inauguration in January 1956.
Carlos Lacerda escaped to Cuba when the country was ruled by the dictator Fulgencio Batista. Lacerda had to flee after Cuban Revolution in 1959.
The coup attempt against JK failed because only far-right agitators inside the Army supported it. JK was moderate and the establishment kept loyal to the democratic institutions.
In 1964, when João Goulart was the president, he didn't have the same luck. The establishment supported the coup against him.
Why did I tell this history? Because it is about a right-wing lame duck president who didn't respect the result of an election and faced impeachment, and far-right agitators.