Political Polarization

Political polarization is the movement of parties, voters and institutions toward opposed positions, with the ground between them emptying out. In the United States it is measurable: roll-call analysis of Congressional voting shows the parties overlapping substantially through the middle of the twentieth century and separating almost completely by the 2010s.¹

Conservatives distinguish two things the word covers. Disagreement about how a country should be governed is the normal business of politics and needs no cure. What has changed is that the disputes now reach subjects a constitution once kept off the ballot, and that citizens have come to dislike the other side as people rather than as opponents.

Key Takeaways

• DW-NOMINATE scores of Congressional roll-call votes place party separation at its widest since Reconstruction.¹⁵
• Affective polarization, meaning hostility toward opposing partisans, has grown faster than disagreement on individual policy questions.
• Conservatives argue that centralising contested decisions removes the local settlements that once contained disagreement.
• James Madison’s Federalist No. 10 treated faction as permanent and sought to manage it structurally rather than eliminate it.²
• Critics argue polarization is asymmetric, driven by one party’s movement, or that it reflects genuine and overdue moral conflicts.

History And Context

James Madison wrote Federalist No. 10 in November 1787 on the assumption that faction is incurable. Its causes are sown in human nature, he argued, and the most common source is the unequal distribution of property. Suppressing faction requires destroying liberty, so a workable constitution manages it instead: an extended republic with many competing interests makes it hard for any single majority to combine, and representation filters passion through deliberation.² The federal division of powers served the same end by keeping most contested questions out of the national arena.

American politics after 1877 produced parties with weak ideological definition. Both contained regional and economic blocs that cut across the left-right line, and the Democratic coalition held northern industrial labour alongside the segregationist South until the 1960s. In 1950 the American Political Science Association’s Committee on Political Parties published a report arguing that this incoherence was a defect, and calling for parties disciplined enough to present voters with clear alternatives and be held responsible for governing.

The parties sorted over the following half century. The Civil Rights Act of 1964 and Voting Rights Act of 1965 began the realignment of the South; conservative Democrats and liberal Republicans thinned and then disappeared. Keith Poole and Howard Rosenthal’s DW-NOMINATE scaling of every Congressional roll-call vote since 1789 records the result: the two parties’ voting ranges, which overlapped substantially through the New Deal era, had shrunk to near-zero overlap in the House by the 2010s.¹⁵

Institutional change compounded it. Primary elections shifted candidate selection to the most committed voters; the Federal Communications Commission abandoned the Fairness Doctrine in 1987; cable news expanded after 1996 and social platforms after 2005, each rewarding intensity over breadth. Shanto Iyengar and colleagues documented the affective turn: by the 2010s partisans reported discomfort at the prospect of a child marrying across party lines at rates that dwarfed the figures of the 1960s.³

The Conservative Position

Conservatives argue that the driver is the centralisation of contested questions, not the temperament of the electorate. When schooling, marriage, medicine, speech and religious practice were settled by states, counties, parishes and families, a citizen who lost an argument in one jurisdiction lived under a different settlement in the next. The stakes of any single election were bounded. As those questions moved to national legislatures, national agencies and national courts, each contest became winner-take-all across a continent, and the incentive to treat the other side as an existential threat followed from the structure rather than from bad manners.

Robert Nisbet’s account of the loss of intermediate association points the same way. Church, guild, neighbourhood, union hall and extended family once gave people identities that crossed political lines and obligations that outranked them. As those bodies weakened, party filled the space, and a partisan identity carrying no other content hardens into tribal membership.⁴

Conservatives also argue that the collapse of shared moral premises removes the ground on which compromise used to stand. Disputes over tariffs or transport can be split; disputes about the nature of the person cannot. Where a society no longer holds a common account of what a human being is and what is owed to one, political disagreement loses its arbiter.

The proposed remedies are structural rather than exhortative: return contested decisions to the lowest competent jurisdiction, restore the deliberative functions of legislatures against rule by agency and injunction, and rebuild the local institutions that give citizens a life outside politics. Conservatives are sceptical of calls for civility that leave the incentives untouched.

Differing Positions

The most substantial reply is that polarization has been asymmetric. Several political scientists argue that DW-NOMINATE shows Republican legislators moving further from the centre than Democrats over the same decades, and that a symmetric account of the problem misdescribes it and blocks any accurate remedy.

A second holds that some polarization is progress. American parties in the 1950s agreed with each other partly because both accommodated segregation. Depolarising on those terms meant excluding the people with most at stake, and clearer parties have made real moral choices contestable at the ballot box.

A third disputes the diagnosis of causation. Survey research finds that the median voter’s positions on most policy questions have moved less than partisan animosity has, which suggests that identity and media environment, rather than substantive disagreement, drive the hostility. If so, decentralisation would not address it.

References

1. Keith T. Poole and Howard Rosenthal, Ideology and Congress (Transaction Publishers, 2007).
2. James Madison, Federalist No. 10 (1787).
3. Shanto Iyengar, Gaurav Sood and Yphtach Lelkes, “Affect, Not Ideology: A Social Identity Perspective on Polarization”, Public Opinion Quarterly, vol. 76, no. 3 (2012).
4. Robert Nisbet, The Quest for Community (Oxford University Press, 1953).
5. Jeffrey B. Lewis, Keith Poole, Howard Rosenthal et al., Voteview: Congressional Roll-Call Votes Database (UCLA, 2026), party-means series.