Retired Cuban leader says Republican primaries are 'the greatest competition of idiocy and ignorance that has ever been'

Fidel Castro has lambasted the Republican presidential race as the greatest competition of "idiocy and ignorance" the world has ever seen, and also criticised the news media and foreign governments for seizing on the death of a Cuban prisoner to demand greater respect for human rights.

Castro's comments came in a long opinion piece carried by official media two days after a Republican debate in Florida presented mostly hardline stances on what to do about the Communist-run island.

Cuba has become an important issue as the candidates court Florida's influential Cuban-American community in an effort to win the biggest electoral prize so far in the primary season.

Castro said he had assumed the candidates would try to outdo each other on the issue of Cuba, but nonetheless he was appalled by the level of debate.

"The selection of a Republican candidate for the presidency of this globalised and expansive empire is – and I mean this seriously – the greatest competition of idiocy and ignorance that has ever been," he wrote.

Castro disputed accounts of the death of Wilman Villar Mendoza, a 31-year-old prisoner, saying he had not been a dissident and had not been on a 50-day hunger strike, as human rights and opposition groups claimed. The retired leader said Villar had been a common criminal sent to prison for domestic violence, and he had received the best medical attention possible.

Washington and several European governments condemned Cuba for his death, and Amnesty International said it had been planning to put Villar on a global list of prisoners of conscience.

Villar had become a cause celebre for opponents of the Cuban government, but was not a well-known figure even among island dissidents before his death.

The Republican candidate, Mitt Romney, said during Monday's debate that Villar had died "fighting for democracy", and that his death highlighted the need to stand firm on Cuba. Washington has maintained a trade and travel embargo on Cuba for nearly 50 years.

Romney's rival Newt Gingrich said he would authorise increased covert operations to bring down the Cuban government. And at another moment of the debate, Romney and Gingrich sparred over whether Castro's soul would go to heaven or hell.

Asked what he would do as president if he found out Castro had died, Romney said he would first "thank heavens" that the revolutionary had "returned to his maker", to which Gingrich replied: "I don't think Fidel's going to meet his maker. I think he's going to go to the other place."

Castro did not refer to the comments specifically in his opinion piece, and said he was too busy with other things to waste any more time analysing the Republican competition.