yitbos
Dershowitz doesn't get it.
For American Jewish liberals Jewishness is identified with leftism/progressivism. Even Israel itself has been justified by most American Jewish supporters as a radical "progressive" state in the midst of reactionary monarchies. Dershowitz has actually said the pro-Israel position is the "true radical position."
So long as Jewishness is defined by something other than Torah and Jewish settlement in Israel is justified in terms other than as a mitzvah from the Torah American Jewish liberals will always be conflicted. In fact, they are inherently conflicted because they are "Jewish liberals."
A couple weeks ago President Obama's remark that Israel exists because of the Holocaust stirred up much hostility in Israel because there the Jewish right to the land, even among the secular, is dated back to Biblical times. American Jewish liberals on the other hand weren't offended at all because they themselves justify Israel's existence as a reaction to the Holocaust. As Caroline Glick (I believe) put it, American Jews are more into "Holocaust education" than either religious or Zionist education.
American Jewish liberals are actually heartbroken that Israel turned out to be something other than the Middle East chapter of the American Civil Liberties Union. And with their reflexive anti-Biblicism (based on their feelings of guilt for introducing the Biblical G-d to the world and being the original "Theocratic conquerors") they are bound to eventually regard Israel the same way they regard the Ten Commandments: as a chr*stian notion against which they define themselves.