Sen. Bernie Sanders has doubled down on his support for some of dictator Fidel Castro's policies, saying that it is "unfair to simply say everything is bad."

Sanders, a self-proclaimed democratic socialist, told CBS News' "60 Minutes" that some of the Cuban dictator's policies had redeeming qualities, such as social welfare programs.

"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?" Sanders said.

Sen. Ted Cruz (R-TX) criticized Sanders on Twitter.

Sanders said in the interview that he "condemns" the human rights violations Castro committed.