Incumbent positioning, ideological heterogeneity and mobilization in U.S. House elections

This article examines whether the need to mobilize citizens pushes incumbents to the ideological extremes in U.S. House elections. We test whether incumbents are more ideologically extreme as the ideological heterogeneity of the district increases and if turnout increases as incumbents become more extreme. These tests combined with the observation that divergence decreases with competitiveness suggest that candidates balance the need to attract swing voters with the need to mobilize supporters. The results also suggest that the growth in elite polarization is linked to the growing ideological heterogeneity in the electorate.