Zionism is not just a cover for anti-Semitism, to the degree that it is, and has been accused of being, but in its own right an accelerant. Especially on the left. Just "unfriended" someone on guess which social medium who I know would not in person be anti-Semitic, nor tolerate it.
He'd be anti-Coughlin, anti-Lindberg, for instance. Maybe, though I'm far from sure, even anti-Farrakhan, so far as Jews go.