"Que viva Fidel" is a 1959 remake of a song that shocked Cuba in 1949, "Que viva Changó", the Yoruba orisha of thunder, lightning, dance and music.
The 1949 song shocked Cuba because it marked a breakout into official popular culture of the Santería religious traditions firmly rooted in the island's Black population.
Changó, though the orisha of maleness, is syncretised with the Catholic figure Santa Barbara, hence that original song.
Even before the victory of the revolution, Fidel became identified with various orishas, and especially Changó. Obviously this was rooted in afro-Cuban culture, which is little known in the United States because 99.9% of those who emigrated initially to the United States after 1959 were upper-class whites (and there were very few Blacks among those who came in later decades also).
Looking at Miami, you'd never suspect that about half, perhaps more, of Cubans are of African descent. Cuba's wars for independence in the 1800s, as well as the 1959 revolution, were centered in the mostly Black eastern provinces of the island.
In addition to the vitriol, lies and slander that will be directed against Cuba and Fidel in the coming days, there will also be much that tries to be objective or even written in admiration.
But almost all will pass over this fact:
Fidel's Cuba is an AFRO-Caribbean nation.
If you want to understand why the United States continues to defy world opinion and maintain its economic blockade against Cuba, you will find part of the reason --a big part of the reason-- in the fact that a song dedicated to the Yoruba deity Changó became one in praise of Fidel.
They hate the Cuban revolution not just because it is socialist, but because it is Black.