A poll published just over a week ago by Vice found Sanders and Biden statistically tied among black voters. Just two days ago, Biden was asked about the poll and denied that Sanders was leading him among any segment of black Americans.

“Why is Senator Sanders leading you with black voters under the age of 35?” Antonia Hylton, a reporter for Vice News, asked at a presidential forum hosted by her outlet on Monday. “He is not leading me, black voters, under the age of — look, just all I know is, I am leading everybody, combined, with black voters,” Mr. Biden responded, engaging in some of the hyperbole he often disavows. Some audience members gathered at an events center here laughed. Mr. Biden did not.

Today the Daily Beast published a story which seems aimed at rattling some of that support for Sanders. The outlet obtained (it doesn’t say how) interviews of Sanders from the 1970s, back when he was leading a fringe socialist party called the Liberty Union Party. In those interviews, Sanders repeatedly compared the situation of Vermont workers to slaves:

“Basically, today, Vermont workers remain slaves in many, many ways,” Sanders said in another interview in 1977, in which he compared the burgeoning service industry in the nearly all-white state to the enslavement of black Americans at the nation’s founding. “The problem comes when we end up with an entire state of people trained to wait on other people.”… In the first interview, published in October 1976 when Sanders was the Liberty Union Party’s nominee for governor, the future senator responded to the announced sale of the century-old Vermont Marble Company to a Swiss conglomerate by calling for worker control of businesses, calling it “absolutely absurd” that the family that owned Vermont Marble could have “the unilateral right” to sell the company without the approval of its employees. “We believe ultimately that companies like Vermont Marble should be owned by the workers themselves and that workers—not a handful of owners—should be determining policy,” Sanders said. “If a worker at Vermont Marble has no say about who owns the company he works for and that major changes can take place without his knowledge and consent, how far have we really advanced from the days of slavery, when black people were sold to different owners without their consent?”

As the Daily Beast points out, Vermont at the time was 99 percent white.

There are some pretty obvious differences between having a job and slavery, starting with a fact that employees at Vermont Marble could choose to quit and either work somewhere else or try to launch their own rival company. But there is actually quite a long history of this sort of criticism of “wage slavery” from the far left. What Sanders was saying about it at the time seems consistent with his other socialist views in the 1970s. Last year, CNN published a review of Sanders’ public statements from this same time period and found he was also a fan of nationalizing major industries:

During this time, Sanders and Liberty Union argued for nationalization of the energy industry, public ownership of banks, telephone, electric, and drug companies and of the major means of production such as factories and capital, as well as other proposals such as a 100% income tax on the highest income earners in America. Sanders also rejected political violence and criticized the anti-democratic nature of communist states such as the Soviet Union. “I favor the public ownership of utilities, banks and major industries,” Sanders said in one interview with the Burlington Free Press in 1976.

This is one of the ongoing criticisms of Sanders from some on the left. His take on slavery (at least his 1970s take) seems to be based on his socialists views about the ownership of capital and class divisions. He sees it as part of a continuum. But that downplays or even ignores racism as a key distinction between slavery and work. Given the widespread focus on identity politics on the left today, that obviously doesn’t play very well.

I’m not at all confident this will get much play in the media but even if it does, Sanders will sidestep questions about it the same way he has about his past socialist views, i.e. hey, that was a long time ago. Still, I do wonder if this was a leak from a rival campaign looking to lay some groundwork for more awkward conversations about his past views.