Zionism has always been highly controversial. It is a political movement but it’s proponents try and paint it as a central and indelible part of Jewish identity - trying to make it seem as if to attack zionism is to attack Judaism. This is of course utter bullshit.
It’s a common tactic of the zionist movement to try and equate anti-zionism with being anti-semetic. But zionism is a nationalist political ideology, not an ethnic identity.
It is not anti-semetic to attack zionism, just as it is not unamerican to attack the Republican Party.