There are indeed people who use anti-zionists as a cover for anti-semitism. There are also anti-zionists who are in no way anti-semitic. There have always been Jews who are very critical of zionism.

For that matter there have been anti-semites who have supported zionism, even when the term anti-semite is used in a restricted sense, to just mean hatred of Jews.

And if anti-semitism is used in a fuller sense, it includes hatred of Arabs, which is now openly expressed by many of the same kind of people who have traditionally persecuted Jews.