Last month, Vermont Sen. Bernie Sanders ruffled a lot of feathers — especially among Florida’s Cuban exile community — when he praised the “literacy program” instituted by Cuban dictator Fidel Castro.

Sanders has repeatedly refused to back down on his comments, defending them in press interviews and debates. Sunday’s debate between Sanders and former Vice President Joe Biden was no exception, as the last two Democrats standing battled over the issue.

As Mediaite previously reported, in an interview with CNN’s Anderson Cooper, Sanders was asked about a video from the 1980s in which Sanders said that the Cuban people didn’t overthrow Castro was because he “educated their kids, gave them healthcare, totally transformed their society, you know?”

Sanders told Cooper:

We’re very opposed to the authoritarian nature of Cuba, but you know, it’s unfair to simply say everything is bad. You know? When Fidel Castro came into office, you know what he did? He had a massive literacy program. Is that a bad thing? Even though Fidel Castro did it?

The comments lit a firestorm on social media, with many viewing Sanders as unacceptably praising Castro, a dictator who oversaw the imprisonment, torture, and murder of thousands of his own people.

Univision’s Ilia Calderón, who joined CNN’s Jake Tapper and Dana Bash moderating tonight’s debate, asked a series of pointed questions about Sanders’ remarks about Cuba and other dictatorships.

Sanders continued to indignantly defend his comments, even going so far as to offer another example, noting China was an “authoritarian society” but still reduced rates of poverty.

Sanders then challenged Biden to defend former President Barack Obama’s own comments about Cuba’s education system.

Biden seemed well-prepared to answer, noting that Obama had been in the process of trying to thaw U.S.-Cuban relations, and reach out to the Cuban people.

Defending authoritarian governments was unacceptable, continued Biden, scoffing at Sanders’ attempt to parcel out narrow accomplishments by the dictators while ignoring their brutal abuses of their people’s civil rights.

“Did China make progress in ending extreme poverty over the last 50 years, yes or no?” Sanders asked Biden.

“It’s like saying Jack the Ripper…” exclaimed Biden, as Sanders cut in: “No it’s not!”

Watch the video above, via CNN.

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