Growing Up in a Polarized Party System: Ideological Divergence and Partisan Sorting Across Generations

Abstract American political elites have increasingly polarized over the past decades, which has inspired much research into mass polarization. We study whether there is a generational component to mass polarization by disentangling period, age, and cohort differences while distinguishing two forms of mass polarization: partisan sorting and ideological divergence. Drawing from General Social Survey and American National Election Studies data, we find that partisan sorting has increased across long-standing and emerging issues, while ideological divergence has not. Contrary to expectations, over-time increases in sorting are clearly driven by changes within generations rather than by generational replacement. On several issues, newer generations turn out to be less sorted than those they replace. This tentatively suggests that, partially as a consequence of demographic changes, generational replacement will gradually lead to less polarization in American public opinion as it converges toward more liberal positions.