Suggests that distancing is the dominant response to poor people by those who are not poor and that distancing, separation, exclusion, and devaluing operationally define discrimination. Examines U.S. classism in the context of theoretical propositions about the moral exclusion of stigmatized others. Describes cognitive, institutional, and interpersonal distancing. Discusses how psychology, however unwittingly, helps sustain class bias. (Contains references.) (SM)