Antisemitism, if you use that word. Jew-hatred, if you want to argue semantics about semites, as many Jew-haters do, when trying to change the subject. It's a disgusting, backward, fucked-up, paranoid frame of mind in which someone believes canards such as how Jews simultaneously are both the worlds communists and socialists and the greatest capitalists. That the Jews control the banks, the media and the government, yet are vile, vermin-like creatures who use subterfuge and crafty pressure to be accepted among polite company. Or that Jews were not targeted and murdered throughout history, most especially not by Hitler and his enthusiastic helpers and passive cowards. And also that the Nazis didn't kill enough Jews.
It is unacceptable from the right. Especially so when they advocate and use violence to spread their hate.
And it is unacceptable from the left, even if all they use are words.