Fox Nation host Rachel Campos-Duffy on Monday was relieved that Sen. Bernie Sanders', I-Vt., socialist ideas were finally getting vetted.

“Bernie Sanders has been a supporter of Communist revolutions and regimes ... He told his class when he was a professor that he was excited when he was hearing about the revolution in Cuba,” Campos-Duffy told, “Fox & Friends.”

Sanders, the front-runner for the Democrats' presidential nomination, doubled down on his support for some of Cuban dictator Fidel Castro's policies, saying in an interview that aired Sunday, "it's unfair to simply say everything is bad."

BERNIE SANDERS DEFENDS FIDEL CASTRO'S SOCIALIST CUBA: 'UNFAIR TO SIMPLY SAY EVERYTHING IS BAD'

Speaking to CBS News' "60 Minutes," Sanders, a self-proclaimed democratic socialist, pointed to social welfare programs introduced under Castro's regime that he described as redeeming, despite the communist dictator's often repressive human-rights violations against Cubans.

"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 told Anderson Cooper.

“He was not supporting a literacy revolution, he was supporting a communist revolution,” Campos-Duffy said.

“What an insult,” Campos-Duffy said.

Fidel Castro relinquished power to his brother, Raúl, in 2011 after nearly half a century in charge of the island nation; Fidel died in 2016.

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In a resurfaced speech given at the University of Vermont in 1986, Sanders praised the socialist policies implemented in Cuba by the Castro regime and criticized bipartisan efforts in the U.S. to tamp down on Castro's spread of communism.

Campos-Duffy said that Sanders supports communism, socialism and authoritarianism.

“It wasn’t very long ago when he said that the American dream was more likely to be found in Venezuela than the United States of America and then he quietly took that off his website, but he hasn’t been held accountable for it and I hope he’s finally getting vetted because this is dangerous," she said.

Fox News' Vandana Rambaran contributed to this report.