Jonathan Chait at TNR asks more or less the same question Jonathan Zasloff asked here: If I support the existence of Israel as a Jewish state, in what sense am I not a Zionist? Chait suggests that I must mean that I no longer support Israel; that gets my point precisely backwards.
Zionism is a loyalty, not a mere opinion.
I support lots of things, including the existence of Israel. I’m loyal to a few. Israel is no longer one of them.