Defying the pundits, Bernie Sanders dominates the struggle for the Democratic nomination by describing himself as a “democratic socialist” and calling for a “political revolution.” True, almost everyone assumes that Hillary Clinton will be the nominee, and this is probably correct. Yet the Clinton campaign stands for nothing — it is what my friend Jeff Goldfarb calls “gray — whereas Sanders has forced the attack on inequality to the center of the stage. Still, there is much confusion concerning the two key words of Sanders’ campaign, “socialism” and “revolution.” Do these words have any meaning or are they only the residues of an earlier stage of world history?

To understand that they do have meaning we have to understand Sanders himself. He is a product of the 1960s, a period in which the word “revolution,” and the ideas of democratic socialism flourished. But whereas most of his generation followed the pied piper of identity politics into the elitism, neo-liberalism and political reaction of the 70s, Sanders was one of a small minority that remained faithful to the ideas of his youth. (Full disclosure: I am another such.) His use of the terms “socialism” and “revolution” reflects this. Let us consider them one at a time.

The idea of socialism cannot be separated from the idea of communism, as originally formulated by such figures as Jesus and Plato. Marx of course was a major figure in this tradition, partly because of his critique of private property and partly because of his analysis of the modern form in which private property is organized, namely capitalism. In the late nineteenth century, socialism became linked to the idea of government ownership of property, and/or management of the economy. The reason for this was that capitalism produced a need for a modern state, and the political movements of the era, including socialism, liberalism and fascism were state-building movements. However, what is crucial to see is that the idea of socialism was never just that of big government. Rather, the idea was to base society on social justice and cooperation, rather than self-interest.

By the 1960s, this meaning of socialism had become clear to all progressives. Thus, the movements of the sixties, such as civil rights, feminism and gay liberation- were all concerned to push the idea of a socialist revolution beyond mere economics, into such spheres as family life. This link was lost in the seventies. But Sanders is reminding us that the idea of socialism was not based on more government, but rather on a different moral, psychological and cultural basis for society.

The same is true for the idea of revolution. In the period in which the main historical activity was building the state, a revolution meant a change in the social class controlling the state. Thus people spoke of “bourgeois revolution” and “working class revolution.” By the sixties, however, the left confronted a new agenda– how to establish a different moral order than the greedy, fearful and frequently murderous one associated with capitalism. Sanders is going back to this idea of revolution, not to armed uprisings and the like.

The point is that there was huge progress made in the ideas of the left — such ideas as socialism and revolution– and this progress was reflected in the movements of the sixties. But just as progress is possible, so is regression. Beginning in the 1970s, the entire meaning of a left was forgotten, marginalized and suppressed, It was not the right or business that did this: it was Bill and Hillary Clinton, and Barack Obama, who embraced the idea that we no longer needed ideas like socialism and revolution, but rather should depend on “growth,” an idea that is neither left nor right. The present inequality is the result of the Clinton/Obama Democratic Party, which is why we so desperately have needed, and now have, a figure like Sanders.