evidence: In "The Eighteenth Brumaire of Louis Bonaparte," Karl Marx famously commented that human beings "make their own history . . . but under circumstances existing already, given and transmitted from the past." The career of Senator Bernie Sanders, who this week ended his second bid for the White House, has illustrated Marx’s point. After getting elected to Congress, in 1991, as an independent democratic socialist—the first self-identified socialist to be sent to Capitol Hill in decades—Sanders spent more than twenty years as a marginal figure. Although he caucused with the Democrats, and even chaired the Senate Committee on Veterans’ Affairs, his leftist views set him apart from much of the Party, including its leadership. Then came the run-up to the 2016 Presidential election, when almost all elected Democrats cleared the field for Hillary Clinton, and Sanders stepped into the vacuum as the anti-establishment candidate. Initially, many political analysts dismissed his campaign as a quixotic venture that would go nowhere. But these analyses ignored the historical "circumstances," which, for Marx, refers to the economic environment, and how they had changed over the previous three decades. [...] The recognition that society is an organic whole in which all sorts of people do indispensable things, many of which go under-rewarded by market economies, has long been the basis of socialism and social democracy. Sanders accepted this solidarity principle a long time ago. Even as he departs the Presidential stage, the "circumstances" are making the egalitarian agenda he promoted more relevant than ever.