A Christian Zionist puts forward an interesting theological explanation for the hostility shown by some Protestant denominations to Israel, as exemplified by the decisions (now suspended) of the Anglican and Presbyterian Churches to divest from companies associated with the Jewish state.
According to the author, these left-leaning Protestant groups adamantly reject a literal interpretation of the bible, preferring instead to view scripture as pure allegory. Thus the existence of a renewed Israeli state in itself offends them, as Israel's rebirth can be interpreted as the fulfillment of biblical prophecy. These churches, the author emphasizes, do not object to Israeli policy so much as to the very existence of the state, and the support that Israel's existence lends to biblical literalists.
The theological element may play some role here, but I'd have to guess that these churches are mostly responding to political considerations and pressure tactics from pro-Palestinian lobbying groups. At the recent Palestine Solidarity Movement conference at Georgetown, for example, I saw numerous workshops explicating tactics aimed at convincing churches to divest from Israel. Churches are clearly a primary target of the divestment movement, and I think churches that are left-leaning anyway are naturally susceptive to this kind of lobbying.