📌 What The Paper Argues

Populism increases affective polarization not only among its supporters but also among non-supporters. The effect on non-supporters grows as the level of populism in a country increases, producing a two-way dynamic: partisan identity tied to populist parties heightens interpersonal animosity, and rising national populism amplifies polarization across the electorate.

📊 Data and Scope

• Uses V-Dem expert rankings of party-level populism paired with CSES (Comparative Study of Electoral Systems) survey measures of affective polarization.
• Covers 185 national elections across 53 countries, enabling a cross-regional test of the proposed two-way mechanism.

🔍 How the Relationship Was Tested

• Links individual-level measures of affective polarization to both individual partisan alignment with populist parties and country-level scores of populism from expert assessments.
• Employs a cross-national analytical design to assess whether effects observed at the party-supporter level persist and expand when populism is more widespread in a country.

🔬 Key Findings

• Replicates prior claims that identifying with a populist party strongly correlates with higher individual-level affective polarization.
• Demonstrates that an individual’s affective polarization is also associated with the overall level of populism in the country, regardless of whether the individual supports a populist party.
• Shows the influence of country-level populism on non-supporters grows as populism increases, producing broader societal polarization.
• Offers an explanation for a common comparative finding: radical-right parties in Western democracies are disproportionately targeted with animosity by supporters of other parties.

💡 Why This Matters

• Highlights a dual pathway through which populism reshapes political affect: partisan identification and ambient national-level populism both intensify interpersonal political hostility.
• Suggests that responses to populism cannot be limited to its supporters; widespread populism can polarize the broader electorate and reshape inter-party animosities.