Affective Polarization: Over Time, Through the Generations, and During the Lifespan.

The continual rise of affective polarization in the United States harms trust in democratic institutions. Scholars cite processes of ideological and social sorting of the partisan coalitions in the electorate as contributing to the rise of affective polarization, but how do these processes relate to one another? Most scholarship implicitly assumes period effects—that people change their feelings toward the parties uniformly and contemporaneously as they sort. However, it is also possible that sorting and affective polarization link with one another as a function of age or cohort effects. In this paper, I estimate age, period and cohort effects on affective polarization, partisan strength, and ideological sorting. I find that affective polarization increases over time, but also as people age. Age-related increases in affective polarization occur as a function of increases in partisan strength, and for Republicans, social sorting. Meanwhile, sorting only partially explains period effects. These effects combine such that each cohort enters the electorate more affectively polarized than the last. [ABSTRACT FROM AUTHOR]