Bernie Sanders is a longtime admirer of Eugene Debs, the labor organizer and political radical who pioneered a distinctly American socialism in the first decades of the 20th century. Before Sanders, Debs was the most successful socialist candidate in American history, winning hundreds of thousands of votes in the final four of his five campaigns for president. He won 6 percent of the national popular vote in 1912, the equivalent, in 2016 numbers, of more than eight million votes

Debs was best known for his thundering attacks on industrial capitalism. A tireless campaigner, he crisscrossed the country denouncing the inhumane conditions of factory labor and berating the capitalist class for its destructive obsession with profit. “In the wage system you and your children, and your children’s children, if capitalism shall prevail until they are born, are condemned to slavery and there is no possible hope unless by throwing over the capitalists and voting for socialism,” Debs declared in a speech delivered at an Independence Day celebration in Chicago in 1901.

But Debs didn’t just condemn his class enemies. He also called on his audiences to imagine a better world — to realize the democratic and egalitarian promise of the American Revolution through collective action. “We live in the most favored land beneath the unbending sky,” he said in a speech in 1900. “We have all the raw materials and the most marvelous machinery, millions of eager inhabitants seeking employment. Nothing is so easily produced as wealth, and no man should suffer for the need of it.” Debs’s appeal, noted the historian Nick Salvatore in his 1982 biography, “Eugene V. Debs: Citizen and Socialist,” was “frequently described by contemporaries as evangelical, and transcended at that moment factional disagreements and led each in the audience to glimpse a different social order.”

Or, as one self-described “hard-bitten socialist” said to the journalist Heywood Broun at the time: “That old man with the burning eyes actually believes that there can be such a thing as the brotherhood of man. And that’s not the funniest part of it. As long as he’s around, I believe it myself.”