My own guess is that Trump is not personally anti-Semitic (in the way that he clearly is, by contrast, sexist). His daughter converted to Judaism to marry a Jewish man of whom Trump seems genuinely fond and who has major influence in the campaign. The wife of Trump’s son Eric is Jewish; Donald Jr.’s wife is Jewish on her father’s side. Trump has Jewish friends and business colleagues. Rather, I believe that he knows so little about the history of anti-Semitism that he doesn’t even realize the links. Once he is challenged on it, he digs in and becomes defensive (I should never have taken down that six-pointed star!) but he doesn’t double down on his attack the way he has when accused of bigotry against other groups.

That the anti-Semitism is unintentional on his part doesn’t make it any less dangerous. By invoking these conspiracy theories without naming Jews, anti-Semitic ideas are introduced without fanfare into the mainstream political conversation while sending encouragement to those white nationalists who fully understand their implications. And so anti-Semitic sentiment and activity rises without anything explicit being said. It serves as a warning that dangerous beliefs can be transmitted even unwittingly if the opportunity presents itself.

Whether Trump is intentional about spreading anti-Semitism is, of course, largely beside the point. Like his more overt expressions of racism, sexism and Islamophobia, Trump’s anti-Semitic comments have made such conversation acceptable again. As a historian, I know that blatantly racist, anti-Semitic, xenophobic public comments by public officials (particularly but not exclusively in the South) were commonplace until the 1960s. I never thought I would hear it today. As a Jew and an American, I am both afraid and ashamed. And I worry this recrudescence of bigotry will long outlast the election.