What accounts for individual differences in the level of politicized ethnic identity among members of an ethnonational diaspora? By politicized ethnic identity, we refer to the disposition to assign priority to the interests of the homeland in the politics of the host society. The question presumes that even the most thoroughly mobilized of diasporas contain members who differ among themselves in the degree to which homeland matters predominate in determining political preferences and behavior. Using a 1999 survey of American Jewry, we establish the level of variation in the political salience of Israel to members of the community, then identify and test the factors that promote or retard such commitment.