Are party activists the party extremists? The structure of opinion in political parties

In re-examining May's law of curvilinear disparity, this article analyzes t he structure of opinion of political parties. May suggests that voters, par ty readers and party activists have different incentives to participate in politics, and therefore voters and leaders have more moderate positions on issues than party activists. This article is based on the extensions of May 's law made by Kitschelt, who argues that curvilinear disparities, although not general phenomena, are bound to occur in specific circumstances. We ha ve focused on the level of cleavage conflict in the system, the variable th at Kitschelt himself found to be critical for explaining party radicalism a mong sub-leaders. Using the Norwegian multiparty system as a test case, we propose that radicalism among party activists is conditioned by the relativ e saliency of different policy dimensions. The empirical analysis, which is based on surveys of MPs, party members and voters in connection with the g eneral election of 1993, gives very little support to our proposition.