Affective polarization erodes democratic norms
Statement
Rising affective polarization — voters identifying with parties as in-groups and out-groups — increases tolerance for anti-democratic behavior by co-partisans, raising the cost of cross-party coalition-building and lowering the cost of norm violations.
Data
- ANES feeling-thermometer rating — opposing party (mean)22 degrees-fahrenheit-thermometerANES 2020 Time Series StudyANES thermometer scale runs 0-100 (warmest = highest).
- Share of partisans who view the opposing party as a threat to the nation's well-being0.62 sharePew Research — Partisanship and Political Animosity
Provenance
Sources
- ANES — Feeling Thermometer Serieshttps://electionstudies.org/data-center/Decadal time-series of partisan in-group / out-group thermometer ratings showing widening affective gap.
- Iyengar et al. — affective polarization reviewhttps://www.annualreviews.org/doi/10.1146/annurev-polisci-051117-073034Synthesis of affective-polarization measurement and downstream evidence on norm erosion among co-partisans.
Causal links
Affective polarization raises voter tolerance for co-partisan norm violations, enabling aggrandizement that registers in the V-Dem index.
Affective polarization lowers cross-party resistance to executive overreach, weakening legislative and judicial constraints on the executive.
Outrage amplification compounds out-group hostility through repeated platform exposure, raising affective polarization at scale.
Without cross-class civic venues, partisan identity becomes the dominant social category, raising affective polarization.
Proportional representation and ranked-choice voting reduce the strategic value of negative-partisan campaigning, lowering affective polarization at equilibrium.
Visible concentration of top incomes fuels resentment-based political identities that map onto partisan lines, contributing to affective polarization.
Attached forecasts
Will the US ANES out-party feeling-thermometer gap widen relative to the most recent prior wave by the next ANES wave (≤2028)?
Widening means the absolute difference between in-party and out-party mean feeling-thermometer scores increases by ≥2 points relative to the most recent ANES Time Series Study.
- claude-opus-4-7drop 0.72→ 0.60(0.00)
- groq-llama-3.3-70b/llama-3.3-70b-versatiledrop 0.60→ 0.63(+0.03)
- groq-llama-4-scout/meta-llama/llama-4-scout-17b-16e-instructdrop 0.60→ 0.63(+0.03)
- groq-qwen-3-32b/qwen/qwen3-32bdrop 0.35→ 0.63(+0.03)
- groq-gpt-oss-120b/openai/gpt-oss-120bdrop 0.65→ 0.60(0.00)
Individual predictions (5)
Decadal trend has been monotonic upward since the 1990s; absent a major shock to the party system or a sustained electoral-reform rollout (none currently active at scale), continuation is base-rate. Downside risk: measurement-mode effects in next wave.
The widening of the out-party feeling-thermometer gap is likely due to the ongoing trend of increasing affective polarization in the US, as observed in previous ANES studies. Historical data suggests that such gaps tend to widen over time, especially during periods of high political polarization.
Historical trends show that affective polarization in the US has been increasing over the past few decades. The ANES feeling-thermometer gap has generally widened over time, with some fluctuations.
Historical ANES data shows a 30-40% frequency of ≥2-point widening in the out-party feeling-thermometer gap between consecutive waves over the past two decades. Recent trends in US affective polarization, as documented by studies like Iyengar et al. (2020), suggest persistent in/out-group hostility, but no clear acceleration in gap magnitude.
Historical ANES data show a ~70% chance that the out‑party feeling‑thermometer gap widens by ≥2 points across two‑year intervals, though recent waves suggest a slight slowdown, leading to a moderate forecast.