In 1981, the Catholic population represented a very large minority group (39.1 percent) whose size was increasing both relatively and absolutely. The size itself provides a bedrock of alienation in that it is more difficult for a large minority to accept its marginal political and economic leverage. In addition, a high degree of overlap between religious affiliation and political party identification suggests that Catholics have been effectively excluded from policymaking, and the refusal of Protestant majority parties to countenance any form of partnership as a mechanism for giving Catholics access to political power has alienated the two main Catholic parties. Catholic marginality also is compounded by their marginal participation in the police, civil service, and judiciary. Further, relative to Protestants, Catholics are more likely to be unemployed or to be employed in low-status occupations. Catholics also are likely to view Dublin as the focus of their national identity and to maintain ties with the South. A majority feel that justice is not fairly administered, and, while there are demographic variations, there is considerable support for the use of violence. Results indicate that Northern Irish Catholics experience significant alienation and suggest that a policy of binationalism is more likely to be effective than the current policy of homogenization. 5 tables and 23 notes.