[Highly intelligent but not very wise has been the perennial failing of that group.]
Jews aren’t stupid. Left wing Jew haters despise Jews for what they think, whether it’s belief in a Jewish deity or support for Israel. Right wing Jew haters despise Jews for what they are - the taint is in the blood. In the worst case, and a Communist dictatorship transpires, a Jew can discard his religion and backing for a Jewish state. Whereas in a Nazi dictatorship, a Jew might be able to lie about his ancestry, but cannot escape the results of a DNA test. In Germany, a single Jewish grandparent meant a one-way trip to Treblinka or Sobibor, terminated by a dry shower.
My observation is the hostility from the Right comes from what they do, not who they are.
A longstanding joke by the alt-Right on Twitter is that they were radicalized by Wikipedia: they read about the “Early Life and Family” of prominent Leftists.