Political polarization
Political polarization denotes the divergence of political attitudes toward ideological extremes, whereby subsets of a population adopt increasingly dissimilar views on parties, policies, and partisans, often intensifying partisan animosity and hindering cross-aisle cooperation.[1][2] This phenomenon manifests in two primary forms: ideological polarization, reflecting substantive differences in policy preferences, and affective polarization, involving emotional dislike and distrust toward out-partisans, with empirical evidence indicating the latter has escalated more pronouncedly in recent decades.[3][4] In the United States, where polarization has garnered extensive study, partisan ideological gaps have widened to historical peaks, as measured by self-reported conservative-liberal identifications, while affective metrics from surveys like the American National Election Studies reveal growing in-group favoritism and out-group hostility since the 1980s.[5][6] Contributing factors include elite-level partisan sorting, whereby political leaders and activists first diverge on issues, cueing mass followers, alongside residential and social self-selection into homogeneous communities that reinforce echo chambers, though direct causal evidence for media-driven mass polarization remains limited.[7][3] These dynamics have yielded legislative gridlock, eroded institutional trust, and heightened risks of political violence, as perceptions of extremism—often overestimated by engaged citizens—fuel mutual recriminations across ideological lines.[8][3] While most pronounced in the U.S., similar trends appear in other advanced democracies, driven by analogous mechanisms like electoral incentives and cultural shifts, underscoring polarization's threat to deliberative governance.[9]