So a party finally takes a stand, and the reaction is tone policing. I'm sure it would have been a more effective strategy to have instead approved a 300-page, highly nuanced policy analysis.
Any exclusive chauvinist nationalist, colonialist ideology is inherently racist. Zionism concerns itself with a single ethno-religious group, so it meets the first criterion. And its goal has been to colonize Palestine, so it meets the second as well. Even the less murderous forms of zionism differ from the bloodthirsty mainstream largely on the issue of how well or badly to treat the indigenous underclass.