If you’re equating the Jewish people with zionism, or conflating being in favor of zionism as somehow being benevolent to the Jewish people as a whole, you are treating the Jewish people as a monolith and are yourself being anti-semitic. Zionism is perfectly compatible with anti-semitism (see for example all those anti-semitic christians who enthusiastically support zionism), and anti-zionism is in itself not anti-semitic (cf Jewish voice for peace).
So making “zionist” a slur has nothing, absolutely nothing to do with being anti-anti-semitic or not.
There’s about 100 million evangelical christians in the US, and a LifeWay poll in 2017 showed that about 80% essentially considered themselves zionists. That’s 80 million. There’s 15.8 million jews worldwide. So the non-Jewish zionists outweigh Jewish zionists by a fair margin. Heck, they outweigh the zionist and the non-zionist jews taken together by a beefy margin, even.