The circumstances today, however, are vastly different. One reason hateful nativism so easily morphs into anti-Semitism in the Trump era is that today Jews really do disproportionately support immigration. The major American Jewish organizations overwhelmingly oppose Trump’s immigration policies. So do rank and file American Jews, according to several polls. Among whites, Jews were dramatically overrepresented in the civil rights movement too.

The segregationist anti-Semites of the mid-20th century and the nativist anti-Semites of today are wrong about Jews’ motives. Jews didn’t support civil rights then—and they don’t support immigrants’ rights now—because they want to subjugate white Christians. They’re just predisposed—because of their understanding of Jewish history—to identify with outsiders and fear ethnically and religiously exclusive definitions of Americanism. But people who demonize African Americans or Latino and Muslim immigrants notice that predisposition, and it leads them to demonize Jews too.

That’s why, in the Trump era, rising nativism and rising anti-Semitism go hand in hand. Before last week, Jewish conservatives might have been forgiven for ignoring this deadly pairing. Now there’s no excuse.