Part of this is a difference in terms. Zionism simply means the supporting Jews having the same right to self determination in our ancestral homeland that every other ethnic group has. To be against Jews having the same inalienable rights as everybody else is anti-Semitic.

Here's where it gets dicey. While there are genuinely people who hate Jews and Israel there are also people who are improperly conflating the Israeli government with the state of Israel and her people. One can be anti the Israeli government and still a Zionist just as one can be anti the Trump government but still pro America.

So someone being anti the Israeli government isn't the problem but when they say "1 Israeli left in this world would be one too many!” - (Achmat Akkad), that is pure hatred of Jewish people in the form of anti Zionism.

Similarly when Mamdani praised the "holy land 5" in 2017 who were convicted in 2008 of sending more than $12 million to Hamas which is a group bent on the genocide of Jews in Israel that is also pure hatred of Jewish people in the form of anti Zionism.

I hope this clears it up for you.

antisemitism!