Nearly five decades ago, the organization that would become the Democratic Socialists of America united around core principles, including universal health care, workers’ rights, and support for the social-democratic state of Israel. That group included such left-liberal luminaries as California Congressman Ron Dellums, the intellectuals Irving Howe and Cornel West, and future New York Mayor David Dinkins. The writer and activist Michael Harrington, whose Democratic Socialist Organizing Committee was a precursor to the DSA, declared in 1975: “I support Israel as an internationalist. Israel is a democratic country whose people are passionately defending its self-determination.” He added that to “preposterously charge” that Zionism is racism—as the United Nations General Assembly asserted in a resolution that year—“is to drain the concept of racism of any serious meaning.” For Harrington and his comrades to speak that way in today’s unsubtle times would be inconceivable. DSA leaders, their organization swollen to 75,000 members, now describe Israel as an apartheid colonialist state. When, on October 7, Hamas and other armed Palestinian groups slaughtered 1,200 men, women, children, and infants, …