The Immigration Act of 1924 effectively slowed to a trickle the previous decades’ flood of immigrants into the U.S., introducing a system of quotas that made Jewish immigration especially difficult—with well-known consequences in the late 1930s and early 40s. In The Guarded Gate, Daniel Okrent argues that the main motivation behind the legislation was eugenics. Richard Starr writes in his review:

From the distance of almost a century, some of the restrictionists of our own day have offered a bloodless defense of the 1924 Act. . . . Patrick J. Buchanan recently presented a pithy version of this argument: “All peoples to some degree resent and resist the movement of outsiders into their space. . . . Our leaders in the 1920s understood this and took steps to halt the migrations until those who had come could be assimilated, and, in a word, Americanized. It worked.”

Except that’s not what those leaders thought they were doing or why they thought they were doing it, which brings us to the less familiar part of Okrent’s story. The men whose vision was embodied in the 1924 act did not by and large believe that the immigrant masses could or even should be assimilated and Americanized. Okrent gives us the view of Kenneth Roberts, who for years had been banging the drum for restriction in the pages of the Saturday Evening Post, the largest and most influential of American magazines in those pre-radio, pre-TV days: “If America doesn’t keep out the queer, alien, mongrelized people of Southeastern Europe, her crop of citizens will eventually be dwarfed and mongrelized in return.” . . .

As Okrent notes, “this ferment of racial analysis was a direct, if almost certainly unintended, product of the Darwinian revolution: once you establish that not everyone is descended from Adam and Eve—and thus not genetically related to one another—anything goes: racial differences, racial hierarchies, racial hatred.” And though eugenics may sound to modern ears like Darwin for Dummies, it wasn’t the dummies who led the parade. It was the best and brightest, good progressives, pioneering conservationists, highly credentialed scientists and intellectuals.

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.