America's political divide is deeper, and more dangerous, than it seems

Only 3 percent of American adults are married to someone from the opposing party, and those couples make up 6 percent of all marriages, the Democracy Fund Voter Study Group paper published in August 2020, “’Til Death Do Us Part(isanship): Voting and Polarization in Opposite-Party Marriages,” found. Partisan conflict in the United States is no longer confined to Capitol Hill or cable news. It reaches into marriages, household decisions, and the basic expectation that neighbors, coworkers, and classmates can keep living together even when they disagree on politics. The numbers behind that strain show a country sorting more deeply and trusting less.

Politics has entered family life

The same study found that about 84 percent of people in opposite-party marriages vote in elections. Even when spouses disagree politically, they are still showing up at the ballot box, carrying their identities into the decisions that shape schools, hospitals, housing, and local government.

Americans cannot choose to live only among people who think like they do. They share homes, child care, church pews, school events, and workplace routines with people whose politics may feel increasingly alien.

The public feels divided, and the feeling itself has power

Research archived in the U.S. National Library of Medicine shows that polarization has deepened over the last 25 years, with Americans increasingly sorting by party identity rather than by moderate views. It changes how people interpret one another’s motives, how they choose friends, and how they judge whether compromise is a virtue or a betrayal.

A 2020 article in PMC, “Polarization in America: two possible futures,” found that 90 percent of Americans believe their country is divided over politics, and 60 percent feel pessimistic about their future. Those figures help explain why calls for a “national divorce” find emotional traction even when separation is not realistic. People may not want to split the country in two, but many already feel as if they are living inside one.

That pessimism carries social costs beyond elections. In a country where 90 percent believe division is the defining condition, everyday disagreements can start to feel existential. School board meetings turn into proxy wars. Workplaces become tense over what can be said, worn, or posted. Neighborhood life grows more brittle when basic trust erodes.

Americans may be more polarized in perception than in reality

Research published by Carnegie Endowment for International Peace on September 5, 2023, found that American voters are less ideologically polarized than they think they are. The misperception is greatest among the most politically engaged Americans, the people who pay the closest attention to politics and often shape the loudest public conversation.

Perception drives behavior. If the most engaged voters believe the other side is more extreme than it really is, they are likelier to support hardline tactics, disengage from shared institutions, or treat compromise as naïveté. The result is a political culture in which exaggeration can become self-fulfilling.

The same Carnegie research places polarization alongside democracy and political violence, treating the divide as a governance and public-safety issue, not just a social one. When partisan identity hardens, it can make intimidation feel justified and civic disagreement feel like a threat to be neutralized rather than managed through law and institutions.

The institutions that still force coexistence

The deeper problem is not only what Americans believe about one another. It is that the places where they have to cooperate are under strain. Marriages are one example, but schools, workplaces, municipal services, and local civic groups all depend on people who do not agree on everything continuing to function together anyway.

A country cannot really be divided like a household with matching apartments, because the daily machinery of life still runs through shared systems. Public schools rely on parents who can coexist across ideological lines. Employers depend on workers who can collaborate after an ugly election. Local governments depend on residents who accept the same rules even when they dislike the people enforcing them.

Carnegie’s Democracy, Conflict, and Governance program studies ways to reduce democratic backsliding, mitigate conflict and violence, and overcome political polarization.