Political polarization in the United States

DW-NOMINATE party medians from Voteview — the canonical direct measure of congressional polarization. Most recent data from Jan 1, 2025.

Key Insight

US polarization is now an elite-driven, education-sorted phenomenon far more than a racial one, and the direct measures contradict the popular 'America is coming apart along racial lines' framing.

Generated by Claude on Apr 16, 2026
Exclude COVID
House Party Median Gap (DW-NOMINATE)

Distance between the Republican and Democratic caucus medians on DW-NOMINATE dim-1 — the canonical direct measure of congressional polarization. Higher = more polarized.

▲ +0.0% YoY

0.93DW1

Trend YoY growth is +0.0%, accelerating by 0 bps/year over the last 166Y. Latest: +0.0%, 2 bps above trend, a 1.0σ deviation.

Level

Change (pp)

y = −0.0% + 0 bps/yr · t

Deviation from trend

Senate Party Median Gap (DW-NOMINATE)

Same measure applied to the Senate — tends to lag the House but has climbed in parallel since the 1980s as moderate senators retired or switched parties.

▲ +0.0% YoY

0.92DW1

Trend YoY growth is +0.0%, accelerating by 0 bps/year over the last 166Y. Latest: +0.0%, 2 bps above trend, a 0.8σ deviation.

Level

Change (pp)

y = −0.0% + 0 bps/yr · t

Deviation from trend

House GOP Caucus Median

Median DW-NOMINATE score of the House Republican caucus — isolates how much of the gap is driven by the GOP moving right vs. Democrats moving left.

▲ +0.0% YoY

0.53DW1

Trend YoY growth is +0.0%, accelerating by 0 bps/year over the last 166Y. Latest: +0.0%, 2 bps above trend, a 2.0σ deviation.

Level

Change (pp)

y = −0.0% + 0 bps/yr · t

Deviation from trend

House Democratic Caucus Median

Median DW-NOMINATE score of the House Democratic caucus — the Democrats' shift is smaller than the GOP's in most post-1980 studies; this series shows whether that still holds.

▼ -0.0% YoY

-0.39DW1

Trend YoY growth is -0.0%, slowing by 0 bps/year over the last 166Y. Latest: -0.0%, 1 bps below trend, a 0.4σ deviation.

Level

Change (pp)

y = 0.0% 0 bps/yr · t

Deviation from trend

White Democratic Vote Share

Share of white voters choosing the Democratic presidential candidate — decomposes the gap from the white side. The structural post-1980 floor sits near 40%.

▲ 31.3%

42.0%

Level

YoY Change (bps)

No data
Black Democratic Vote Share

Share of Black voters choosing the Democratic presidential candidate — decomposes the gap from the non-white side. Consistently 80%+ for 50 years; the recent slow drift off that level is the main story.

▲ 1.2%

83.0%

Level

YoY Change (bps)

No data
Hispanic Democratic Vote Share

Share of Hispanic voters choosing the Democratic presidential candidate — the demographic whose partisan alignment is shifting fastest. Starts 1980 (first cycle with reliable exit-poll samples).

▼ 7.1%

52.0%

Level

YoY Change (bps)

No data
Diploma Divide (Dem Vote Gap)

Percentage-point gap between college and non-college Democratic presidential vote share (all voters, all races). The canonical direct measure of educational polarization — signed with the recent direction: positive means college-educated voters are more Democratic. Near zero through 2012, then opens after 2016.

▲ 300.0%

12.0pp

Level

Change (pp)

No data