"[T]o what she believes is antisemitism on the left."
First, the use of "believes" implies that she doesn't know what antisemitism on the left is. She wrote a book about it, not? She's written articles on it, right? Hasn't she appeared in a recent episode of Real Time to explain this?
Second, she's not providing a feeling-based response. She's describing antisemitism in a twenty-first century context. She used her experience as extra weight to her argument about her ability to communicate the urgency of hatred toward Jews. Given that she's written extensively on the subject, I think there is something worthwhile to consider. Many other scholars have written on what is described as the "new antisemitism," first coined in France as « le nouvel antisémite. »
I watched the episode three times. What she said is that both left and right-wing are capable of their hatred and demonization of Jews and Israel, but differed in their rhetoric and explicitness.
What gives you any agency to tell victims of antisemitism that they have no agency to communicate research on said experiences?