Sometime before World War II, many U.S. Jews began celebrating a third ritual meal on Passover, as Jenna Weissman Joselit writes:

A supplement to, rather than a substitute for, the . . . first and second seders commonly observed outside of Israel, it was usually held during the latter part of Passover. More of a communal gathering, a public event, than an intimate family occasion, its origins date to the interwar years. In a replay of that era’s cultural politics, when both socialism and Zionism held high cachet among East European Jewish immigrants, some attribute its creation to the Arbeter Ring (Workmen’s Circle); other, equally insistent voices, credit the Labor Zionist Farband. There’s no consensus, either, on when the third seder made its debut. Some say 1922, others 1927, and still others aren’t sure whether it’s 1932 or 1937.

No matter. At some point within a few years of one another, both communal organizations harnessed the structure and sensibility of the traditional seder—or, more to the point, perhaps, that of the model seder conducted in their respective afternoon schools—to their own ends. Emending, interpolating, politicizing, contemporizing, and theatricalizing the venerable Haggadah, the Arbeter Ring produced a text called Naye hagode shel peysakh (the new Passover Haggadah); the Farband, in turn, produced its own Hagode shel peysakh farn dritn seder (Passover Haggadah for the third Seder). . . .

The Farband linked the age-old story of deliverance to the establishment of a just and equitable homeland for the Jews, while the Arbeter Ring, for its part, linked the same story to the struggle for economic justice and political freedom more generally. . . . Well into the 1980s, people in New York and Chicago turned out in droves for the annual third seder of their choice, held in a hotel ballroom grand enough to accommodate over 1,000 guests. For a generation or two, the event drew a crowd even in places where the number of Jews was much smaller. They came for the camaraderie, not the food: to lay claim to and celebrate a common history, a shared ideology, and a better future.

Two extraordinary events demonstrate something important about Israel’s most fervent adversaries. One was a speech given at something called The People’s Forum (funded generously by Goldman Sachs), which stated, “When the state of Israel is finally destroyed and erased from history, that will be the single most important blow we can give to destroying capitalism and imperialism.”

The suggestion that this tiny state is the linchpin of a global, centuries-old phenomenon like capitalism goes well beyond anything resembling rational criticism. Even if Israel were guilty of genocide, apartheid, and oppression—which of course it is not—it would not follow that its destruction would help end capitalism or imperialism.

The other was an anti-Israel protest that took place in front of New York City’s Memorial Sloan Kettering Cancer Center, deemed “complicit” in Israel’s evils. At organizers’ urging, participants shouted their slogans at kids in the cancer ward, who were watching from the windows. Given Hamas’s indifference toward the lives of Gazan children, such callousness toward non-Palestinian children from Hamas’s Western allies shouldn’t be surprising. The protest—like the abovementioned speech—deliberately conveyed the message that Israel is the ultimate evil and its destruction the ultimate good, cancer patients be damned.

The fact that Israel’s adversaries are almost comically perverse does not mean that they can be dismissed. If its allies fail to understand the obsessive and irrational hatred that it faces, they cannot effectively help it defend itself.