The Republican National Committee Thursday attacked Sen. Bernie Sanders, I-Vt., after a CNN report detailed the self-described Democratic socialist's calls to nationalize "utilities, banks and major industries" while leading a far-left political party in the 1970s.

"If there were any doubt that Democrats are the party of socialism ..." RNC spokesman Michael Ahrens said in a tweet linking to the report, which detailed Sanders' political positions as the standard-bearer of Vermont's Liberty Union Party. During the 1970s, Sanders ran for public office a total of four times as the Liberty Union Party's nominee -- twice for governor and twice for U.S. Senate.

During that period, Sanders called for a 100 percent tax on incomes above $1 million, reasoning that no one could spend more than that in a lifetime. He also called for "socialized medicine," "the public ownership of utilities, banks and major industries," and said corporations that attempt to leave towns and cities should be converted into "worker-controlled enterprises" through "legislation which will bring about the public ownership of the major means of production."

Sanders left the Liberty Union Party in 1977, following his second unsuccessful run for governor the year before. In his farewell remarks, he predicted that "if workers do not take power in a reasonably short time, this country will not have a future."

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The comments reportedly came when Sanders was in his early and mid-30s, and are part of a laundry list of controversial statements linked to him that support socialist policies and governments. In 1985, while mayor of Burlington, Vt., Sanders described breadlines in Nicaragua as "a good thing."

"In other countries, people don’t line up for food," Sanders said at the time. "The rich get the food and the poor starve to death."

In another interview, Sanders told a Vermont TV station, "As a socialist, the word socialism does not frighten me and I think it's probably fair to see the government of Nicaragua is primarily a socialist government

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That same year, Sanders praised Cuban dictator Fidel Castro, telling an interviewer that "just because Ronald Reagan dislikes these people, doesn't mean that people in their own nations feel the same way."

"In 1959 ... everybody was totally convinced that Castro was the worst guy in the world and all of the Cuban people were going to rise up in rebellion against Fidel Castro," Sanders said. "They forgot that he educated their kids, gave their kids health care, totally transformed the society."

Three years later, in 1988, Sanders returned from a visit to the Soviet Union and praised the Communist state's public transportation system, as well as what he described as a "variety of programs for young people, and cultural programs which go far beyond what we do in this country."

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Last month, Sanders drew condemnation from Florida Democrats when he refused to describe Venezuela's Nicolas Maduro as a "dictator," and claimed that "there are still democratic operations taking place" in the South American nation, which has been beset by economic chaos and a push for Maduro's ouster.

Sanders, who made a strong bid for the Democratic nomination in 2016, has been a pace-setter in the early-voting states of Iowa and New Hampshire. Recent polls have shown him neck-and-neck with former Vice President Joe Biden, who has yet to formally enter the race, atop the Democratic field.

Fox News' Adam Shaw and Joseph Wulfsohn contributed to this report.