In the United States, politics is dominated by two large parties whose members must draw votes and contributions from a large fraction of the population and which therefore should be relatively immune from being swayed by any one group. Yet narrow interests carry the day against the clear preference of the majority much of the time. Using the example of the agrochemical industry in four countries - Britain, Germany, Austria, and Sweden - political scientist Lorelei Moosbrugger posits a continuum of political vulnerability that predicts how different combinations of institutions should affect a political system's ability to resist interest group pressure.

Lorelei Moosbrugger is an assistant professor of political science at the University of California, Santa Barbara.