The class bias of associational activity gives meaning to the limited scope of the pressure system, because scope and bias are aspects of the same tendency. The data raise a serious question about the validity of the proposition that specialinterest groups are a universal form of political organization reflecting all interests. As a matter of fact, to suppose that everyone participates in pressure-group activity and that all interests get themselves organized in the pressure system is to destroy the meaning of this form of politics. The pressure system makes sense only as the political instrument of a segment of the community. It gets results by being selective and biased; if everybody got into the act the unique advantages of this form of organization would be destroyed, for it is possible that if all interests could be mobilized the result would be a stalemate.
''the semisovereign people'' (1960)