A myth haunts conversations about proportional representation in America. It is the belief that proportional representation requires a parliamentary system. We’re here to kill this myth. As comparative political scientists have long known, proportional representation can work well with a presidential system. It long has in several democracies.

But proportional representation is more than just compatible with a presidential system. It could help restore the functionality of American democracy and reduce the prospects of a democratic erosion. The greatest threat to our system of government stems from the divisive and polarized nature of the two-party system. Americans are turning against each other. In contexts of deep societal polarization, politicians and voters alike tend to put partisanship above democracy. For this reason, deep polarization is the prologue to executive overreach, illiberalism, and authoritarianism. Proportional representation would likely attenuate this dynamic.

In this article, we hope to convince you of two points.

The first is that presidentialism and multiparty democracy often work well together. Despite some concerns about the combination in the early 1990s, the last three decades have shown it to be resilient and stable in a meaningful number of democracies.

The second point is that the current U.S. combination—presidentialism atop deep and deepening polarization in a two-party system—has become dysfunctional. The conditions that made presidentialism in America stable—a moderate two-party system, with considerable overlap between the parties and relatively nonideological politics—have vanished. They are not likely to return soon, if ever. We need reform. Proportional representation would allow one or two more parties to become important contenders, would enlarge possibilities for building coalitions across parties, and would likely attenuate polarization.

Let’s start with a basic understanding of institutional design across democracies. On one dimension (the system of government), contemporary democracies broadly divide into parliamentary, presidential, and semi-presidential systems. In parliamentary systems, voters elect a legislature, and then the legislature chooses a leader (usually a prime minister), who is typically the head of the largest party. In presidential systems, voters elect a legislature and also separately elect a president as head of government. The president has some unilateral powers, but the legislature provides a balance and a check. Semi-presidential systems have both a directly elected president and a prime minister chosen by the parliament, and both have important powers.

On a second dimension—the electoral system for the lower chamber of the legislature—contemporary democracies broadly divide into majoritarian, proportional, and mixed systems. In almost all majoritarian systems, voters choose representatives in single-member districts. Because voters in single-member districts tend to treat third parties as spoilers or wasted votes, this system generates two dominant parties at the district level. In proportional systems, voters choose representatives in multimember districts, and legislative seats are assigned in proportion to a party’s vote share in the district. A larger number of seats per district makes it easier for more parties to win seats. In mixed systems, voters choose some representatives through single-member districts and some through multimember districts.

The United States is a majoritarian, presidential democracy. Though that seems natural to many Americans, it is an unusual combination by global standards. The United States is one of only four electoral democracies that have lasted at least ten years with this combination. (The other three, which we view as semi-democratic, are Ghana, Liberia, and Sierra Leone.) Presidential democracies are prevalent, especially in Latin America, but most of them opt for proportional representation for electing the lower chambers of their legislatures. Majoritarian electoral systems are actually more common among parliamentary democracies: For example, the United Kingdom and Canada both combine parliamentary systems with single-member electoral districts.

So we come to our first point: Proportional representation (PR) and presidentialism has already proven a successful and resilient combination in quite a few countries. Examples of robust, stable democracies that use this combination include Costa Rica, Cyprus, Chile, and Uruguay.

These democracies have exhibited effective collaboration between presidents and legislatures. Chile restored democracy in 1990 after 17 years of military dictatorship, and as was the case for much of the 1932-73 period, its combination of multipartyism and presidentialism has functioned generally well since. For decades, Uruguay and Costa Rica have also had presidential systems with proportional representation for the lower chamber (or, in Costa Rica, the sole chamber) of the national congress. Uruguay reestablished democracy in 1985 after 12 years of authoritarian rule; before the 1973 coup, it had a long democratic heritage that combined presidentialism (from 1952-66 as a popularly elected nine-person executive with a fixed four-year term) and PR. Until 1971, electoral competition revolved mainly around two traditional parties; since redemocratization, the country has had three main parties. Costa Rica has the oldest democracy in the Global South, and its democracy has combined presidentialism and proportional representation since 1950. In addition, Venezuela’s democracy, which also combined PR and presidentialism, functioned relatively well from 1959 until the 1980s.

In short, the combination of presidentialism and proportional representation has a proven track record in several democracies around the world.

Now to our second point, which will make up the bulk of this essay: The greatest danger we see is in the United States maintaining its current dysfunctional combination—presidentialism atop a deeply polarized two-party system.

In 1990, political scientist Juan Linz famously argued that presidentialism is inherently perilous, with a tendency to collapse under the immobilism and gridlock that would arise from the “dual legitimacy” of both the legislature and the president claiming to be the true representative of “the people,” especially under a fragmented multiparty system. But for Linz, the United States was the exception—the exemplar of stable presidential democracy. Linz concluded that if presidentialism were to work, it would depend on a party system with moderate, nonideological parties, as the United States had during the postwar period.

For much of the twentieth century, the combination of presidentialism and single-member House districts with first-past-the-post elections in most states worked relatively well for large swaths of Americans. U.S. democracy had blemishes, especially the deep infringements of civil rights for Black Americans and the subnational authoritarian regimes that dominated the Southern states until 1965. But following the enactment of the Voting Rights Act that year, the U.S. political system became a more inclusive democracy that functioned well in many respects.

In recent years, however, many scholars, politicians, journalists, and voters have become increasingly concerned about the dysfunctionality and polarization of American politics. Things that were utterly unimaginable even ten years ago—a democratic breakdown or deep erosion in the level of democracy—have become significant risks. Roiling partisan hatreds, illiberal norm-breaking, and threats of violence are damaging American democracy, potentially putting it in danger.

Democracies need to be agile enough to produce public policies that satisfy citizen demands and needs while providing checks on executive power and preventing presidents from usurping power and undermining the authority of legislatures and courts. The old two-party system that reigned from the 1930s until the ’80s was based on relatively nonideological parties at the national level. Both Democrats and Republicans had conservatives and liberals within their ranks, and partisan labels often meant little. Presidents could and did win support from the other party for some important policy initiatives. For example, Medicare passed with overwhelming bipartisan support in 1965.

This has changed. As American politics has nationalized and polarized, Republican members of Congress overwhelmingly support Republican presidents and oppose Democratic presidents on most important issues. Democrats act the same in reverse. In an era in which parties are defined nationally by their President, few individual members of Congress can carve out separate identities for voters. Representatives are tied to the popularity of their party’s President, so they have sound reasons to ensure that their President is as popular as possible if they want to be in the majority—which almost all of them do.

Likewise, partisans in Congress with an opposition President in the White House have every incentive to undermine that president’s popularity, since an unpopular president is a drag up and down the ticket. In a highly polarized and closely divided country, the balance of power in Congress hinges on presidential approval ratings.

Unified government and divided government in the United States now lead to two very different conditions, neither of which produce healthy executive-legislative bargaining. Under unified government, presidents have a majority in the legislature, which means they are more likely to pass their programs. However, because partisan lawmakers generally overwhelmingly support major initiatives of presidents from their side, there is little meaningful separation of powers. This can be easily abused. Congressional Republicans, for example, showed no interest in meaningful oversight of Donald Trump during their period of unified government.

Under divided government, presidents today have little legislative success on major issues, as the opposition party now commits its legislative powers to stopping the President’s program from passing and its oversight powers to investigating potential wrongdoing in the administration. These conditions lead to legislative gridlock on important issues. In turn, gridlock encourages presidents to push the limits of executive power, knowing there is no point in trying to seek congressional approval for major policy initiatives. However, this is an unstable way to make policy; it is subject to easy reversal by future administrations or by the courts.

Over time, this leads presidential administrations to react more strongly to previous administrations by reversing their predecessors’ policies, which becomes destabilizing for economic investments and foreign policy, since the administrative state has the most delegated authority over economic regulation and international affairs. The moderating features of the old party system have faded, and we see no possibility of resurrecting them.

The challenge for the United States is a familiar one that many democracies have struggled to manage: “pernicious polarization,” in which partisan cleavages split society into two warring camps that see each other not as fellow citizens, but as enemies to be permanently defeated. Under such conditions, democracies commonly fail. This kind of polarization describes the collapse of democracy in Venezuela after 1999 and Hungary after 2010, among many other examples. Both were once thriving democracies.

The way out of such destructive polarization is through partisan realignment that alters the binary, zero-sum nature of conflict. Often, institutional reform is necessary to break this dynamic. This is why we are considering proportional multiparty democracy as an intervention—to facilitate realignment and allow a stronger political center to emerge. As long as a strong political center exists, most presidents tend to gravitate toward it, because that is where majorities are usually made. But under the current electoral system, that center is collapsing. Proportional representation is necessary for new, electorally viable center-oriented parties to emerge, particularly on the political right.

How would presidentialism work with a multiparty Congress? Here we return to our first point: The new scholarly consensus is that multiparty presidentialism can work just fine. Presidents build coalitions in many ways, and they frequently succeed in passing their programs. As long as moderate parties are well represented in the legislature, presidents (except for those with strong illiberal tendencies) typically move toward the policy middle, often showing remarkable flexibility in response to changing political winds—sometimes to the frustration of their parties.

In multiparty systems, presidents have various ways to build majorities. The most common and effective way is through multiparty cabinets. To help facilitate a governing coalition in the legislature, presidents typically allocate positions and portfolios in their cabinet among the parties, often in proportion to party strength. Many presidents can hold together multiparty coalitions across the executive and legislative branches, which allows them to pass preferred policy. Not surprisingly, cabinets form more easily when coalitions are smaller and have more ideological overlap.

But even if a president can’t build a majority, a minority government (i.e., one that does not have a majority in both chambers of Congress) does not necessarily lead to immobilism. Instead, presidents bargain with opposing parties on an ad hoc basis. In some ways, this can be more responsive to public sentiment. A minority government that builds majority coalitions on an issue-by-issue basis is most likely to reflect majority sentiment on every issue. Of course, it can also lead to deadlock. Deadlock is most common under highly polarized party systems. Indeed, under divided government, it is now the norm in the United States—which is, of course, the problem.

Pre-electoral coalitions are common in multiparty presidential democracies, and they affect how cabinet posts are allocated. Parties that endorse another party’s candidate offer organizational infrastructure, civil society connections, and access to campaign funds. In exchange, they get policy concessions and coalition appointments, including at the cabinet level.

Were the United States to adopt a proportional electoral system for the House, we expect that something similar would happen here. A cautious reform intended to limit fragmentation of the party system might produce four electorally important parties: MAGA Republicans, moderate Republicans, moderate Democrats, and progressive Democrats. Depending on the details of a PR system, a few smaller parties might win seats as well, representing some more niche perspectives or constituencies. Presidents would seek to build governing coalitions in Congress, just as they do in multiparty presidential democracies around the world. A multiparty House would still elect a speaker. But with more parties in the legislature, any winning coalition would have to include the party with the median legislator. And with multiple parties, the party with the median legislator would necessarily be the focal point of bargaining.

Though many institutional changes might help American democracy work better, the zero-sum fight for power that dominates politics now makes most changes difficult. The first order of business must be to realign U.S. politics in ways that engage and effectively represent the diversity of the country while also breaking the pernicious polarized binary that generates “us versus them” politics. Proportional representation for Congress is unique among proposed reforms in creating opportunities to realign the party system, and to reshape our political imagination by drawing new, more fluid lines of conflict.

Enacting proportional representation could be done by ordinary legislation; it does not require a constitutional amendment. The elections clause in Article I, Section IV of the Constitution gives Congress the authority to decide how its own elections should be run, a power it has used in the past to mandate single-member districts.

Could such a change conceivably pass? Members of Congress are increasingly frustrated with the hyperpartisanship of Congress, the endless trench warfare, and the power of party extremists in a polarized two-party system. Proportional representation could fix that. The vast majority of members would still get reelected, just under different voting rules. One advantage of proportional representation for members of Congress is that it effectively takes away the danger of being redistricted or gerrymandered out of a job every decade.

There is no evidence that a two-party system makes presidentialism function better. If a two-party system works well with presidentialism, it is only when that system produces relatively nonideological, moderate parties. Whatever risks there are in combining presidentialism and multipartyism in the United States, they are fewer than doing nothing and maintaining the divisive and dysfunctional us-against-them status quo.