Well, first I think it's wise to point out that the answer by @Dreamer was already talking about "any wing zionists" therefore leftwing zionists would fall under that (I disagree on the consideration that was done afterwards, but I think we agree on the existence of these people). Zionism is a liberation movement of the Jewish people, I think it's important to understand this, jews are a people before being the followers of a religion (I'm myself an agnostic jew). The view that judaism is only a religion is originally a Christian/Western perspective.
Peoplehoods have a right to self determine, the problem arises when a peoplehood doesn't have a specific land to selfdetermine in. Most Jews didn't inhabit the land that they considered their homeland, (not everybody considered it their homeland in the same way), but the only place that would resonate with the jewish people enough to band togheter in order to achieve a self determination that could make us capable of avoiding persecutions, was Israel. Reality proved this to be right, when mass emigrations started to happen, to escape persecutions in Europe (before the Shoa), one of the main destinations for jews, in search of a better future, was Israel.
I don't think jewish liberation needs to come at the cost of the palestinian people, but that doesn't make me want less to have a self determination for my people. I think there is space in that land for two peoples.