US Senator Bernie Sanders and US Senator Elizabeth Warren speak on the first night of the second 2020 Democratic US presidential debate in Detroit, Michigan, US, July 30, 2019. Photo: REUTERS/Lucas Jackson.

I view Bernie Sanders from the perspective of a historian knowledgeable about Jews and the American Left. Historically considered, he is the ideological heir of a forgotten leftist sectarian named Daniel De Leon.

Born in 1852 to a Sephardic Jewish family in Curaçao in the Dutch West Indies, De Leon studied in Europe before coming to the US. He received an advanced degree from Columbia University, but was denied a tenured teaching position. Then De Leon found his passion in radical politics. First involved in milder socialist movements and a radical mayoral campaign to topple Tammany Hall, De Leon moved on to lead the militant Socialist Labor Party (SLP).

Supporting the unionization of mass production workers, De Leon championed the International Workers of the World (IWW) — before denouncing the IWW as insufficiently revolutionary. This move was typical of his “rule or ruin” doctrinaire Marxism.

De Leon died in 1914, but the SLP lived on, and his posthumous influence grew abroad. Lenin complimented him for influencing the Bolsheviks.

Like De Leon, Sanders is a Jewish socialist. But the differences appear stark. Sanders is an American-born perennial candidate and officeholder, not a Marxist theoretician. De Leon’s faith in the coming classless society appears to have morphed for Sanders into his loathing of billionaires. Nevertheless, Sanders is a true believer in something very much like De Leon’s signature doctrine: “Impossibilism,” or knee-jerk rejection of anything short of revolutionary change.

De Leon believed that practical economic and political reforms — for example, union campaigns for higher wages or governmental social welfare legislation — were worse than useless. He wanted Revolution Now. He cheered for recessions and depressions, expecting they would accelerate the final collapse of capitalism.

Bernie Sanders early in his career joined the Socialist Workers Party, claiming that “the source of war in the Mideast … is the existence of Israel.” As a campaigner, Sanders talks vaguely about Scandinavian-style democratic socialism; yet as a Vermont mayor, he honeymooned in the Soviet Union, admiringly visited Nicaragua’s Sandinista regime, and lauded Castro’s Cuba. Sanders in those days disdained FDR’s reformist New Deal. Now he hires young campaign staffers who identify as anarchists or Marxist-Leninists.

Sanders, as a congressman and US senator, has typically preferred radical purity to shaping practical legislation with a chance to pass. Daniel De Leon would have approved.

Sanders has, belatedly, rediscovered his Jewish roots. For the first time, he now reminds voters about his relatives killed in the Holocaust, and that as a young man, he spent a few months at Israeli kibbutz Shaar Ha’amakim. His shrill condemnations of Bibi Netanyahu as a “racist,” and his menacing threats of an aid cutoff to Israel tell a different story. Israel-haters like Linda Sarsour and Rep. Rashida Tlaib (D-MI) are campaign surrogates. Jewish Democrats prefer Biden three-to-one.

During a different era, De Leon not only rejected Zionism but dismissed movements to end the persecution of Jews as distractions from fighting for the Socialist Revolution. Buoyed by utopian hopes for an unlikely youth revolution at the polls, Bernie Sanders’ resurrection of De Leon’s “Impossibilism” under a different name may prove the last hurrah of Jewish socialism in America.

Historian Harold Brackman is coauthor with Ephraim Isaac of From Abraham to Obama: A History of Jews, Africans, and African Americans (Africa World Press, 2015).