What is remarkable about this is that it was not part of his prepared remarks. The bulk of this section appears to be extemporaneous.
The text:
While the Shoah has a central role in Israel’s identity, it is not the reason behind its founding, and it’s not the main justification for its existence. That extreme characterization of that mistaken view is that Western powers established Israel in 1948 based on their own guilt; at the expense of Arab peoples who lived there. Therefore the current state is illegitimate and should be wiped off the face of the map. This flawed argument is not only in defiance of basic humanity dignity, but in plain defiance of history. It is in defiance of ancient history as told in biblical texts and through archaeological evidence. It ignores the history of millennia. Several thousand years of history leads to an undeniable conclusion: the establishment of the State of Israel in modern times is a political reality with roots going back to King David and the time of Abraham and Sarah. The argument for Israel’s legitimacy does not depend on what we say in any speech. It has been made by history; it has been made by the men and women who made the desert green; by Nobel prizes earned; by groundbreaking innovations and enviable institutions; by lives saved; by democracy defended; by peace made; by battle won. There can be no denying the Jewish people’s legitimate right to live in peace and security in a homeland to which they have a connection for thousands of years.Notice also that what makes this effective is that he is doing what I recommend pro-Israel activists do - he uses the proper framework of Jewish history.
Too bad too many Jews can't do the same in defending Israel.
(h/t Arsen Ostrovsky)