The use of Khalidi to claim Palestinian identity now is a kind of recent fabrication, as implied here, is to misread him. As Oncenawhile noted, the process of retroactive identification with the deep past is characteristics of all national communities: many people are discovering their Jewishness because of a  500-centuries buried link, via some ancestor or name, with the Jews of the Iberian peninsula, though in the meantime they were thoroughly assimilated, as  Spanish Catholics etc.