(CNN) Bernie Sanders harshly criticized the wealth of US senators during his first campaign for office in 1971, calling it "immoral" that half the members of the Senate were millionaires.

Sanders' decades-old comments , which were picked up in December 1971 by the Bennington Banner, a local Vermont newspaper, are resurfacing as the US senator from Vermont has acknowledged that he is now a millionaire in large part due to his 2016 best-selling book, "Our Revolution."

In a statement to CNN, Sanders campaign spokesman Josh Orton said, "Yes, it is true: Senator Sanders said in the 1970s that it is immoral that the government too often represents the interests of the super-wealthy and large corporations — and yes, it is also true that Senator Sanders has continued to demand a change from that for his entire life."

Orton continued, "As the son of an immigrant who grew up living paycheck to paycheck, Senator Sanders believes elected officials should represent the interests of working people, not corporations, special interests or the ultra-wealthy. This view has guided his work in politics, not the pursuit of personal wealth. Senator Sanders' family has been fortunate, and he is grateful for that because he knows the stress of economic insecurity. That is why he works every day to ensure every American has the basic necessities of life, including a livable wage, decent housing, health care and retirement security."

Sanders defended his newfound wealth in an interview with the New York Times . "I wrote a bestselling book," Sanders said. "If you write a bestselling book, you can be a millionaire too."

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