Opinion | How to Fix America’s Two-Party Problem

In early 2020, Representative Alexandria Ocasio-Cortez, the progressive Democrat from New York, was asked to speculate about her role under a Joe Biden presidency. She groaned. “In any other country, Joe Biden and I would not be in the same party,” she said, “but in America, we are.”

Ms. Ocasio-Cortez’s frustration with the two-party system reflects the frustration American voters feel every time they step into the voting booth, when they find themselves stuck with the same two choices — and, in most places, only one with any shot at winning.

As a new Congress sputters into gear, this rusty binary split — a product of our antiquated winner-take-all electoral mechanisms — is key to understanding why our national legislature has become the divisive, dysfunctional place it is today. It is why more than 200 leading political scientists and historians (including one of the authors of this essay) signed an open letter in 2022 calling on the House of Representatives to adopt proportional representation — an intuitive and widely used electoral system that ensures parties earn seats in proportion to how many people vote for them. The result is increased electoral competition and, ultimately, a broader range of political parties for voters to choose from.

In 2024 fewer than 10 percent of U.S. House races were competitive. In a vast majority of districts, one party or the other wins by landslides. Driven by a decades-long geographic sorting that has concentrated Democrats in cities and Republicans in rural areas and reinforced by partisan gerrymandering, this split electoral landscape has fostered a polarized climate that becomes more entrenched with each election.

The heart of the problem is the system of single-winner districts, which give 100 percent of representation to the candidate who earns the most votes and zero percent to everyone else.

Winner-take-all is the electoral software that generates two dominant parties and relegates third parties to playing the role of spoiler and wasting their supporters’ votes. This leads to the same high-stakes contest every two years between the same two parties, resulting either in domination by one or in divided and paralyzed government by both.

The winners push through as much of their agenda as they can while they hold power. Losing parties often refuse to work with the other side.

In less polarized political times, winner-take-all systems can do a decent job of reflecting public opinion and maintaining democratic stability, but when a nation is deeply divided and large numbers of people fear that they will not be represented at all, the result is an erosion of trust in government and rising extremism and political violence. As the political scientist Barbara F. Walter has observed, a majority of civil wars over the last century appear to have broken out in countries with winner-take-all systems.

No democracy can survive long in the face of this much division and distrust. It’s hardly surprising, then, that more than two-thirds of Americans want to see major changes in our political system. Roughly the same proportion wish they had more than two parties to choose from.

They’re right: Two parties competing in winner-take-all elections cannot reflect the diversity of 335 million Americans.

The Fix

We ended up here not by any conscious choice. The framers of the Constitution never addressed congressional electoral systems. Rather, an election that only one party wins, with a simple plurality, operates as a kind of factory setting for American democracy, one that we have neglected to update, despite radically changed circumstances. As a result, we feel trapped by a system we backed into without thinking much about it.

But what if we aren’t trapped? Most established democracies already use proportional representation. The switch from winner-take-all to proportional elections has been the most common major electoral system change among democracies in recent decades. Here’s how it would work in the United States:

That’s proportional representation. Voters vote as they do today, but because districts have multiple members rather than single members, it allows several candidates to win seats without a majority of the votes. When the winning threshold goes down, the number of viable parties goes up. So multiple candidates from multiple parties can represent a district, giving millions more Americans the opportunity to vote for a winning candidate, whether that candidate is a Republican or a Democrat or a member of another party.

This brings us closer to the vision of founders like John Adams and James Madison, who both warned against the dangers of two dominant parties (or factions). As Adams wrote in 1776, Congress “should be in miniature, an exact portrait of the people at large. It should think, feel, reason and act like them.”

What would that look like in 2025? How many parties would there be? To find out, we analyzed data from Nationscape, a large survey that polled hundreds of thousands of Americans on their political preferences. We used those answers to distribute voters among six hypothetical parties.

Offering Americans a choice among multiple parties doesn’t just give them a clearer voice in how and by whom they are governed; it also opens up possibilities for new political coalitions, which can in turn lead to the passage of broadly popular legislation. Our politics may seem intractable today, but on issues from gun control to immigration to education reform to A.I. regulation, winning coalitions are hiding in plain sight.

It also works better with bigger legislatures, but the U.S. House has been locked at its current size for more than a century. From the beginning of the House in 1789 until the early 20th century, its membership grew roughly in line with the U.S. population. At the start, there were about 34,000 constituents per representative; by 1911, that number had grown to more than 200,000 — much larger than the founders intended but still manageable. Today the average district holds more than 760,000 people, which is far too big for any one representative. As a result, tens of millions of Americans are represented by House members they did not support and in a highly polarized environment that leaves people feeling that they are not represented at all.

The fix for this problem is to expand the membership of the House of Representatives to reflect the size and diversity of the U.S. population in the 2020s rather than the 1920s. According to many political scientists, the optimal total number of members of the House and the Senate combined is equal to the cube root of the nation’s population. Legislatures in democracies around the world roughly align with this ratio; the U.S. House did, too, until its size was frozen by law at 435. Today the cube-root rule would give us a House with 593 members.

To see how these reforms would work in practice, consider Massachusetts:

Not only would right-leaning voters in Massachusetts get federal representation, but the candidates they would help elect would most likely differ from right-leaning candidates elected in Florida or Wyoming. The same is true of the state’s liberals and progressives, who would most likely elect different candidates from those in Texas or Nevada.

If proportional representation was used nationally, it would recreate the ideological diversity that is currently suppressed by the two-party system. To see a picture of how that could play out with multimember House districts, we used Redistricter, a mapping application for analyzing political and demographic data. Here’s what it might look like.

The big benefit of proportional representation is that tens of millions more Americans would feel represented in Congress. It would also effectively eliminate partisan gerrymandering and most likely increase representation of racial, ethnic and religious minorities. In all, it would be a better way to run one of the largest and most diverse countries on the planet.

Eight Words

Many Americans believe the two-party system is inherent to the American constitutional design. But the nation’s framers didn’t intend it, nor is it found anywhere in the Constitution. Rather, the shape of the House of Representatives is mandated by a mere eight words of federal law, which requires “no district to elect more than one representative” — 435 districts, 435 members.

The law as it exists today was passed in 1967, to address concerns that white-dominated Southern states would exploit multimember districts to marginalize their Black voters, but versions of it have been in effect since 1842. Before then, states regularly used multimember districts to elect their congressional representatives. None of those multimember districts, however, have ever been proportional. All used a form of bloc voting — a majoritarian system in which voters can support as many candidates as there are seats, making it impossible for minority-supported candidates to win. But under proportional representation, bloc voting is impossible because each voter gets a single vote.

That’s another thing about proportional representation: As a voter, you wouldn’t do anything substantially different from what you do now. You’d receive your ballot and pick the candidate you wanted to represent you in Washington. What would be different is that you would have more candidates and parties to choose from, and seats would be awarded in proportion to each party’s total vote share in a multiwinner district. The winners could be reported right away. No new voting machines or procedures would be required.

And the law could be changed to allow for proportional representation tomorrow.

Can This Actually Happen?

Any big electoral reform raises big questions.

First, if Congress is already dysfunctional with two parties, why would it work better with five or six? The quick answer is that Congress would do what every other multiparty legislature in the world does — build a majority governing coalition out of multiple parties. Party leaders would negotiate to assemble their coalitions and allocate leadership roles and committee posts to reflect the bargains they’ve made.

If, for example, the 2026 election were held under proportional representation, the Democratic Party coalition might reorganize into three parties competing separately for seats in Congress — the Progressives, the New Liberals and the New Populist Party. Each party could appeal to different constituencies, including many that currently feel ignored or alienated by the two-party system. By spreading out responsibilities, Congress could operate in a more decentralized, committee-oriented manner, with the House speaker playing a less powerful role. This is how Congress operated in the mid-20th century, a more fluid era.

Elections for the Senate and the presidency would remain as they are. But with a multiparty legislature, we would expect coalitions of multiple parties around the strongest presidential candidates, with cabinet appointments that reflect the winning coalition. This combination has proved durable in many countries.

And contrary to popular belief, we wouldn’t have to move to a parliamentary system of government. Most countries with presidential systems use proportional representation to elect their legislatures. The United States is one of only four stable(ish) presidential democracies in the world that use a winner-take-all system to elect their legislature. The other three are Ghana, Liberia and Sierra Leone.

Would sitting members of Congress ever approve these reforms? Many of them agree that their institution is not working. Interviews with retiring members show just how dysfunctional, chaotic and difficult Congress has become — and why so many representatives now call it quits after a short time in office.

It’s not surprising, then, that calls for reform are starting to come from inside the House. In November, Representative Marie Gluesenkamp Perez, Democrat of Washington, and Representative Jared Golden, Democrat of Maine, proposed establishing a select committee to examine electoral reforms, including proportional representation and House expansion; last week they reintroduced it as a top priority in the new Congress. Meanwhile, incumbents who fear losing their jobs should expect to be re-elected under proportional representation, since they would benefit from the advantage of being well known.

A more serious obstacle is the leaders of the two dominant political parties, who are unlikely to support reforms that weaken their power. Then again, party leadership has been described as the worst job in America. And elected leaders do sometimes support significant reforms when voters become so disillusioned that they demand them.

Most of us, politicians and voters alike, have spent our whole lives in this broken system. But imaginations can expand, and conditions that seem unchangeable can change. They often do in a crisis like the one we are living in now. This is a rare moment of openness to reform, combined with and triggered by the dysfunction in American politics. We should seize it.