We don’t hear this kind of rhetoric very often in American politics, on prime-time TV. But Bernie is right: Bloomberg’s gains are ill-gotten. In fact, all the wealth that the ultrarich hoard and leverage in their own interests has been stolen from the working class and from the planet we share.

But at the February debate in Nevada, Sanders suggested a deeper reason that “ billionaires should not exist .” After Michael Bloomberg asserted that he “worked very hard” to earn his more than $60 billion fortune, Sanders responded : “You know what, Mr Bloomberg, it wasn’t you who made all that money. Maybe your workers had some role in that as well, and it is important that those workers share the benefits.”

Bernie Sanders loves to antagonize billionaires, even if it hurts their feelings . Usually, Sanders rails against the way they have used our political system to enrich themselves at the expense of the working class. Over and over again, Sanders points out that politicians like Pete Buttigieg oppose pro-worker policies like Medicare for All, because their campaigns are funded by billionaires and insurance company executives.

The Vampire in the Workplace

The most fundamental way that the very wealthy obtain their ill-gotten gains is through the exploitation of labor.

Capitalism is an economic system characterized by a conflict between two major social classes. On the one hand, there are capitalists, a tiny minority of bosses, bankers, and landlords who own almost all the productive property in society; on the other, workers, the vast majority of whom own almost nothing.

Yet workers are the ones who do almost all the productive labor: building our cities, producing the food, teaching our children, nursing the sick, maintaining the electrical grid, programming our computers, and constructing and transporting goods from cars to clothes to medicine to iPhones. Whether or not they like their jobs, workers have to do this work because the wages they get in return are the only way we can buy what we need to survive.

Capitalists do none of this labor. But they have one huge advantage over workers: in order for workers to do the labor they get compensated for, they have to use the productive property, or the capital, that the capitalists own — factories, machinery, trucks, office buildings, raw materials, farms, restaurants, expensive software, even intellectual property like patents and copyrights. It is the synthesis of these two factors, labor and capital, along with the natural environment from which both draw, that is the source of all of society’s wealth.

Capitalists like Michael Bloomberg would agree with the picture so far: Bloomberg provides one half of the equation, and the hundreds of thousands of workers whom he, his contractors, his suppliers, and his investments employ provide the other half. That he gets compensated more than his workers — in fact, more than all of them combined — is fair, he would argue, considering that he is contributing so much capital.

But, as Karl Marx explained in Capital 150 years ago, this exchange is anything but fair.

First of all, while workers are compensated for their time, their pay rates do not reflect the amount of value they produce for their employer. Think about it: if workers were fairly compensated for everything they provided to their boss, where would the boss’s profits come from? And why would their profit-obsessed boss hire them in the first place?

To illustrate this unequal exchange, take the example of a bakery. A baker making ten cakes a day might get paid $160 for a day’s work, or $20 an hour. This wage is enough for the baker to live on, and it seems fair compared to other jobs. The baker could do a lot worse.

But if each cake sells for $50, and the raw materials and business overhead only account for $10 of each cake, the baker’s labor is producing $400 for the company every day. After paying wages, the company’s owners take in $240 in profit per worker per day!

This additional value, produced over and above what the worker needs to survive, is called “surplus value.” This surplus value is, in effect, stolen from each worker, every day and every hour — and this, not Bloomberg’s hard work, is the primary source of his fortune.

Instead of allowing it to be sucked up by a small number of capitalists to enrich themselves, socialists believe that this surplus value should be used for the social good, as determined democratically by the whole society. Ending exploitation doesn’t mean distributing the surplus entirely to individual workers — some of the wealth workers create must be invested in future production, some of it must be used to fund public goods that benefit everyone (like roads and medical research), and some of it must be used to provide for the non-working population. But socialists object to letting a few individuals get enormously wealthy off of socially created wealth and letting them tyrannically decide how that wealth is used.

Second, the capital that the capitalist contributes to the labor process, such as buildings, machines, and roads, is itself the product of workers’ prior labor. That the capitalist owns this product of yesterday’s labor and uses it to extract more surplus value from today’s workers is an injustice in itself. As Marx wrote, “Capital is dead labor that, vampire-like, only lives by sucking living labor, and lives the more, the more labor it sucks.”

Defenders of capitalism claim that capitalists are rewarded for risk-taking. Billionaires like Michael Bloomberg, the story goes, put it all on the line when they invest in a new business: if the business fails, then much of their capital vanishes. Profits reward successful risk-takers who put up capital for ambitious or innovative business ventures.

But this rationalization assumes what it needs to show: that capitalists are entitled to their capital in the first place. In fact, the capital they wager on markets is itself the product of stolen labor.

They are not entitled to rewards from risking that capital, any more than a gambler is entitled to their winnings on a bet they made with stolen cash. And, regardless, no one deserves to be rewarded with billions of dollars while millions of people suffer in poverty.

Vampire-like, Bloomberg has made billions by exploiting the living labor of millions of anonymous workers around the world whose blood, sweat, and tears helped to build his empire and have given him the opportunity to buy the Democratic presidential nomination.