Charting multidimensional ideological polarization across demographic groups in the USA

Area of Science:

• Political Science
• Sociology
• Computational Social Science

Background:

• Debate exists on whether ideological polarization has increased or if voters have merely sorted into ideologically aligned parties.
• Understanding the dynamics of ideological shifts and partisan alignment is crucial for analyzing contemporary political landscapes.

Purpose of the Study:

• To develop a methodology for quantifying multidimensional ideological polarization.
• To analyze the temporal movements of political and socioeconomic groups within a two-dimensional ideological space.
• To investigate changes in ideological distance and partisan sorting over time.

Main Methods:

• Developed a novel methodology to embed respondents from the American National Election Studies into a two-dimensional ideological space.
• Utilized a wide array of political, social, and economic topics for ideological measurement.
• Identified demographic attributes to track group movements and ideological changes over time.

Main Results:

• Income and racial groups show increased alignment with political parties, but their ideological distance has not widened.
• Significant ideological divergence between the Democratic and Republican parties observed over the past 30 years, with both moving from the center.
• Democratic voters exhibited increased ideological heterogeneity after 2010, suggesting a decline in partisan sorting.

Conclusions:

• The study confirms an increase in ideological polarization between the two major parties, not solely due to partisan sorting.
• Demographic sorting into parties has occurred, but it does not fully explain the growing ideological gap.
• Recent trends indicate a potential decrease in partisan sorting among Democratic voters, highlighting evolving political dynamics.