On Saturday, April 27, a gunman attacked worshipers in a synagogue in Poway, Calif., killing one person and injuring three. The suspect in the shooting is a nationalist who has professed a hatred of Jews, immigrants and other minorities, as well as liberals and leftists who push for social change.

Two responses to the shooting have emerged. Civil rightsactivists are calling for progressive solidarity. They see the shooting as part of a broader culture of white nationalism that requires scapegoats to preserve inequality and white supremacy. Conservatives, on the other hand, argue that the left — specifically, Rep. Ilhan Omar (D-Minn.) — is responsible for stoking anti-Semitism. They identify the source of anti-Semitism primarily as Muslims and people of color — before Omar, it was Tamika Mallory and Rep. Keith Ellison (D-Minn.) — in an attempt to convince Jewish Americans that they should not make common cause with these groups.

At this moment of finger-pointing, we would do well to remember an incident that occurred 70 years ago this summer: the Peekskill riots. At the time of the riots in 1949, anti-Semitic violence was fomented by anti-radical, nationalist sentiments, just like today. And just as in the aftermath of the Peekskill riots, people in power now have a choice: to try to pit minority and progressive groups against one another in the name of nationalism, or to try to forge an internationalist solidarity that lifts up marginalized people across the world.

Peekskill shows us what happens when America chooses the former.