I make a comment stating my opinion and I get banned on this Zionist subreddit.

Zionism is the social liberation movement of the Jewish people, the belief that Jews deserve the right to self-determination, merely the belief that Israel has the right to exist. If you believe any of the above, YOU are a Zionist. Jews debated the merits of Zionism before Israel existed, and these debates were deep and plentiful. Today, half of the world's Jews live in Israel. It won't disappear without a war. If you believe Israel does not have the right to exist *today*, you are antisemitic.