The current polarization of elites in the U.S., particularly in Congress, is frequently ascribed to the emergence of cohorts of ideologically extreme legislators replacing moderate ones. Politicians, however, do not operate as isolated agents, driven solely by their preferences. They act within...

This paper investigates the relationship between the size of interest groups in terms of voter representation and the interest group's campaign contributions to politicians. We uncover a robust hump-shaped relationship between the voting share of an interest group and its contributions to a...