I wish Bernie spared as much nuance for the Democratic Party as he does for Fidel Castro

Asked about his past backing of Fidel Castro’s communist government in Cuba during an interview with 60 Minutes, Sanders began by saying, “We’re very opposed to the authoritarian nature of Cuba,” before adding, “but, you know, it’s unfair to simply say everything is bad.”

In a 1985 letter newly obtained by HuffPost in which Sanders debated running for governor, he wrote: “Whether I run for governor or not is really not important. What would be a tragedy, however, is for people with a radical vision to fall into the pathetic camp of the intellectually bankrupt Democratic Party.”

Vermont senator and Democratic presidential candidate Bernie Sanders once said that he was "physically nauseated" by a speech made by President John F. Kennedy when Sanders was a young man, because Kennedy's "hatred for the Cuban Revolution [...] was so strong."

"Kennedy was young and appealing and ostensibly liberal," Sanders reminisced in a 1987 interview with The Gadfly, a student newspaper at the University of Vermont. "But I think at that point, seeing through Kennedy, and what liberalism was, was probably a significant step for me to understand that conventional politics or liberalism was not what was relevant."

In the same interview, he also criticized Jesse Jackson's decision to try and affect change by "working within the Democratic party" and offered some pointed remarks about Walter Mondale.

Sanders told The Gadfly that endorsing the Democratic ticket in 1984 and "campaigning for Mondale [...] was a very difficult thing to do."

"When I'd go around talking about Walter Mondale I would say that if elected president, I felt, Walter Mondale was going to be a pretty bad president," explained Sanders. "Now sometimes you may have to make painful decisions."

"If you go around saying that Mondale would be a great president, you would be a liar and a hypocrite," concluded Sanders. "That is not what I was saying."

Sanders's remarks about Kennedy, Jackson, and Mondale are in keeping with the Independent senator's long history of criticizing the Democratic Party.

In a Rutland Herald article published the following year, Sanders explained the crucial difference between himself and Jesse Jackson: "'Jesse believes that serious social change is possible within the Democratic Party. I don't.'"

And in a 1989 op-ed in the Burlington Free Press, Sanders lambasted "the corporate-controlled Democratic and Republican parties," and praised the National Organization of Women "for supporting the need for a progressive third party in this country."

"Like millions of other Americans, NOW understands that the Democratic and Republican parties are intellectually and morally bankrupt," Sanders wrote.

"We do not have an effective national political movement which is prepared to fight for power," argued Sanders, "and which challenges the basic assumptions and priorities of the corporate-controlled Democratic and Republican parties – two political parties which have no substantive ideological differences and are, in reality, one party – the party of the ruling class."

“I am not now, nor have I ever been, a liberal Democrat,”

“They have no ideology. Their ideology is opportunism.”

In an op-ed in the New York Times in January 1989, he called the Democratic and Republican parties “tweedle-dee” and “tweedle-dum,” both adhering in his estimation to an “ideology of greed and vulgarity.”

"I think that nationally, the party has on issue after issue sold out so many times that if you go before the people and say, 'Hey, I'm a Democrat,' you don't usually generate a lot of enthusiasm."

In November 2011, Sanders criticized Democrats for their response to the Budget Reform Act of 2011, saying the super committee to develop a deficit reduction plan shouldn't look at cuts in social security or Medicare.
"My suggestion was literally to the Democratic leadership, simply change the name of the party from the Democratic Party to the Republican-lite versus Republicans and say, 'Yeah, we're bad, but we're not as bad as these guys,'" said Sanders on the Thom Hartmann Program.