In 1959, Miquilena became the owner and director of the newspaper "El Clarín". Over time, he progressively became a strong opponent of the government of Rómulo Betancourt (second presidency 1959-1964) over its opposition to the Cuban government under Fidel Castro and its alleged repression of leftwing political groups. However, Miquilena never agreed with guerrillas, calling them a "respectable mistake", saying "A 20 year old who decides to risk his life deserves respect. That's what made me a defender of the people who were fighting the battle against the armed forces, even though in privacy I was a fierce enemy of the guerrilla. It was a mistake that cost us a lot. If we channeled the democratic struggle from the beginning, with all the strength we had, through a rational and institutional way, who knows if the story would be different." In 1961, Miquilena joined the Democratic Republican Union (URD) party and he became a Representative for the state of Falcón in the Venezuelan Chamber of Deputies. In 1964, he left the staff of "El Clarín", quit the URD, and retired from political life. For the next 30 years, he dedicated himself to business, becoming a landowner and industrialist.