It doesn't seem unlikely that people who are in an outgroup would come up with ideas that overturn established ideas. In case of the Bolsheviks, it's not at all surprising that the Jews would be with the people who were not staging pogroms. But you must admit that the people who post these things are not trying to make an intelligent, sophisticated argument like you are, but instead want to say "JEWS BAD". Which is why they bring it up when it's something they don't like and never when they do!

This has to be the most tortured argument you’ve ever written here. So he’s possibly or even probably right, but you think most of the people who agree with him don’t understand the nuances of why he’s right, and therefore… what exactly? He’s wrong? But you didn’t say that. And even if you had, you would have been engaging in a fallacy.

Further, you imply your belief that anti-Semitism simply falls from the sky. Negative opinion of Jews is always arbitrary and exists as a first order principle, animating and directing all subsequent opinions such that they are inherently invalid, yea? But then why do so many people across so many cultures and nations develop these opinions in mutual isolation? Why do people raised within intensely pro-Jewish cultures (as the West) spontaneously develop negative opinions about the Jewish ethnic cohort? Pattern recognition seems a far greater possibility than “muh papa didn’t like ‘em”.