Charting multidimensional ideological polarization across demographic groups in the USA

Is the growing divide in American politics due to actual ideological polarization, or are voters simply sorting more cleanly into the “right” party for their views? This study tackles that question using a quantitative, multidimensional approach inspired by techniques in data analysis and embedding.

Using decades of data from the American National Election Studies, the authors map individual political opinions—across a wide range of social, economic, and policy topics—into a two-dimensional ideological space. This allows them to track how various demographic groups move through ideological space over time.

Surprisingly, while income and racial groups increasingly align with specific parties, their actual ideological positions have remained relatively stable. The real driver of polarization appears elsewhere: Democrats and Republicans as a whole have grown further apart, each drifting away from the ideological center—though at different rates. Moreover, since 2010, Democratic voters have become more ideologically diverse, suggesting a recent reversal of the long-standing trend toward partisan sorting.

This research offers a more nuanced, data-driven view of polarization in the U.S., highlighting the importance of multidimensional analysis in understanding complex social dynamics.

Reference: 

Charting multidimensional ideological polarization across demographic groups in the USA
J Ojer, D Cárcamo, R Pastor-Satorras, M Starnini
Nature Human Behaviour, 1-11 (2025)