Zionism isn't being Jewish, it's being pro-Israel and its intentions of establishing a unified control of the area. Joe Biden and Donald Trump are Zionists, neither are Jewish in faith or ethnicity. Bernie Sanders is Jewish, but against Israel's expansion of the borders and acts it does.
It's like how you can be against Israel and not be Antisemetic, or be Antisemetic and be pro-Israel for reasons from "I want them exported to there" to "They will allow the Kingdom of God to come to Earth".
I am against Israel's apartheid state, and I am against it's ethnic cleaning of the area. Just as I am for any nation who aims to do that, like Turkey and Russia. But I don't explicitly hate Turkish or Russian or Israeli citizens blindly because their government that they don't have direct control over does horrible acts.
Zionism ≠ Jewish
Jewish ≠ Zionism