Why are American Politics so Polarized?

– By Jeff Brittain

Whether it is beneficial or detrimental to policy-making it is undeniable that polarization, combined with super-majority requirements, makes policy-making more complicated and difficult to undertake. Considering that both a polarized party system and super-majority requirements are firmly rooted in American Politics, it is important to understand whether their effects on policy-making are negative or positive. While some argue that these features of American Politics create stability, prevent radical change, and encourage prudent decision making; others argue that polarization and super-majority requirements reduce the quality of legislative outcomes and the capability for meaningful policy-making.

The “Filibuster” and Policy-Making

There are various super-majority requirements in the American political system, however, most relevant to this study are the U.S. Senate rules concerning filibusters and clotures. The Senate rule known as the filibuster allows U.S. Senators to hold the floor almost indefinitely and extend debate on a bill in order to amend it, and more commonly to prevent it from passing. (Sinclair, p. 241) If the opposition is to end the filibuster and pass their bill, they must resort to a cloture vote which requires a super-majority of three-fifths of the Senate, or typically sixty votes. (Sinclair, p. 242)

Perhaps the most obvious result of this system is that it prevents certain policies from even being considered. For example, a Senator might not suggest or support a piece of important legislation, that they otherwise would have, because they know it will face a filibuster and there is not a strong enough coalition to invoke a cloture. With this in mind, it is evident that the most detrimental effect of the extended debate system is that with the increase of polarization [to be discussed], the U.S. Senate has essentially become a super-majoritarian institution, with little hope of passing ambitious legislation. As the APSA put it, “The present cloture rule goes so far in giving individual Senators the right to speak that it interferes with the right of the majority to vote. It is a serious obstacle to responsible lawmaking.” (APSR, p. 65)

Since the 1950s, the use of the filibuster to prevent legislation has dramatically increased from 1 filibuster per session of Congress, to about 30 filibusters per session by the 1990s. (Sinclair, p. 243) Cloture votes have increased even more dramatically than filibusters, and are now almost double the number of filibusters per session of Congress. Despite this, the cloture has become less and less effective at preventing the filibuster, with only about half of the filibusters being overturned by successful cloture votes. (Sinclair, p.243) The increase of filibusters and clotures is evidence of the polarization of policy preferences occurring in the Senate.

Given the rise in polarization and the decreasing effectiveness of cloture votes, it seems reasonable to suggest that the cloture rule should be reformed. Even the 1950 APSA report on a strong two-party system, advocates amending the super-majority requirement for invoking cloture. As the APSR states, “The present cloture rule should be amended. The best rule is one that provides for majority cloture on all matters before the Senate.” (APSR, p. 65) Majority decision-making is more democratic, and will prevent the minority from disturbing the policy-making process and altering its outcomes. In the polarized American political climate we must respect the winners, or we will all be losers, making compromises on political outcomes that nobody likes. For example, during the recent passing of healthcare reform, many of the features that were most important to the majority party, such as the “public option”, were removed as the bill was amended in order to gather more support. Furthermore, redundant and foolish compromises, such as the “Cornhusker kickback”, would not be a risk nor a necessity for passing ambitious and controversial legislation, such as healthcare reform, if super-majorities were not required. Overall, the super-majority requirements of the U.S. Senate exacerbate a problem known as, “Death by a Thousand Cuts”; where by a bill is amended and changed to the point that its reform potential becomes effectively void. (Patashnik, p.33)

The current state of Polarization in American Politics

As stated above, the increase in filibusters and decline in the success of clotures is one indication of polarization. However, perhaps a more convincing indication is the statistical evidence provided by the DW-NOMINATE algorithm. Using data on voting patterns and voting tendencies of Senators, the algorithm effectively estimates the position of all legislators according to two dimensions; a liberal-conservative dimension and a second dimension measuring variation on racial, regional and social issues. (McCarty, p. 4) When the Senators of the recent 107th congress are plotted on a graph it reveals several things. First, there is a distinct gulf between the Democrats and Republicans on the liberal-conservative dimension. (McCarty, p. 4) This gulf represents the polarization of parties that has occurred and the large gap in preferences resulting from the move of both parties to the left or right. Interestingly, such a level of partisan polarization, as exists today, has not been seen since the 1920s. (McCarty, p. 4) Second, and surprisingly, the members of each party are closely aligned on the 1st dimension of liberal-conservative measure, but on the 2nd dimension, measuring social issues, both parties, but particularly the Democrats, are polarized from within. (McCarty, p. 4) The Democrats are especially polarized across the social dimension of the DW-NOMINATE algorithm, which might explain why, even with a super-majority, they were unable to gain the support necessary for certain healthcare proposals and for invocation of cloture.

When polarization creates two strong ideologically defined parties, which may be distant from each other but internally cohesive, it can be a positive for policy-making. However, in the current political climate, polarization has not only moved each party further to the left or right, but has also moved members within each party further from one another in policy preferences.

Causes of Polarization in American Politics

Understanding the causes of polarization in American politics will help to shed light on its inherent problems. Since the mid-1970s, there has been a trend in American politics of increasing polarization. (McCarty, p.3) In correlation with the increase in filibusters and cloture votes, measures of polarization, in both the house and the senate, have shown dramatic increases since the 1970s. (McCarty, p.5) What explains the breakdown in bipartisanship and widening of the gap in policy preferences between the dominant parties? “Southern realignment” is often an explanation provided for the increase in polarization, but as Nolan McCarty explains, even without southern democrats included in the calculation, the increase of polarization is, “…almost identical.” (McCarty, p.5) Another explanation commonly provided is that a decline in participation has spurred polarization. Declining participation is a likely contributer to polarization, as we will see later on, but ultimately, I argue that polarization is actually a result of an increase in income inequality.

Since the 1960s, election turnout rates for the U.S. have declined by almost 15%. (Fiorina, p. 514) Correlating with the trend in polarization, election turnout rates are now at their lowest levels since 1924. (Verba/Schlozman/Brady, p. 74) The reduction in participation that has occurred is just one effect of a widening gap between the rich and the poor in the United States. This is simply because money, rather than time, is the most powerful method of participation in the political system. For example, the top two income groups form less than 10 percent of the population but donate more than half of all money that goes to political campaigns. (Verba/Schlozman/Brady, p. 77) As Verba, Scholzman and Brady wisely note, “When money replaces time at the principal form of political currency, the playing field is no longer level.” (Verba/Schlozman/Brady, p. 75) The evidence presented above also suggests, that in the climate of polarization, the preferences of the poor are easily overpowered by those of the rich. Such a system of polarization could not be healthy for a democratic society.

The foundational cause of both the reduction in participation and the increase in polarization is the increasing gap between the rich and the poor. When plotted on a graph, the change in the GINI index of family income (a measure of income inequality) highly correlates with the polarization index. Beginning in the early 1970s, the gap between rich in poor began to dramatically widen reaching its highest levels since the 1920s. (McCarty, p.6) The most obvious explanation for the link between income inequality and polarization is that the gap in income between rich and poor has created a gap in economic policy preference. This has manifested in the polarizing of both parties, but in particular, the Republicans have moved to the right. As McCarty explains, “…partisanship and voting are increasingly tied to income with income levels enjoying economic growth becoming more Republican while low income voters have remained Democrats.” (McCarty, p. 7)

Polarization and Bipartisanship

Why is polarization a problem? Polarization might not present such a problem, if the U.S. Senate did not essentially become a super-majoritarian institution. In a majoritarian legislature, the median voter theorem would likely apply, bringing policies to the middle of the political spectrum and preventing legislative gridlock. However, due to the structure of American political institutions and the increasing need for super-majorities to prevent filibusters, polarization has become an obstacle for reaching the bipartisan agreements necessary to pass legislation. The pivotal rather than the median voter, has become the most important player in politics. Pivotal voters are those legislators whose support is critical to the overcoming of a veto or filibuster. (McCarty, p.8) This is what has created the need for many of the ridiculous political deals that occur such as the “cornhusker kickback”.

One of the most distinctive features of American politics is that it is highly fragmented. This means that power and authority is highly dispersed between American political institutions and within those institutions such as Congress. As Morris Fiorina explains, “Federalism, the separation of powers, checks and balances — the fundamental institutions of the United States operate to hinder coherent action and obscure responsibility for government action.” (Fiorina, p.521) Such fragmentation often makes it near impossible for the incumbent party to effectively legislate without forging coalitions and gathering support from members of the opposite party. Therefore, bipartisanship is a vital and crucial part of creating legislation.

The problem with the current state of American politics is that the polarization of parties has eroded the ability of congress to engage in bipartisanship. As Nolan McCarty put it, “Given the role of bipartisanship in forging the coalitions responsible for many of Congress’s legislative landmarks, it should be noted with some alarm that this glue is drying and cracking.” (McCarty, p.2) The increase in polarization and subsequent decrease in bipartisanship has made it exceedingly difficult to build the cross-party coalitions that are often necessary to create super-majorities against filibusters.

Further empirical evidence of the damaging effect of polarization on policy-making is provided by the measurements of the gridlock interval, or the preference difference between pivotal voters. Like much of the data described in this paper, the length of gridlock interval correlates with measurements of polarization. Since the late 1970s the width of gridlock intervals has increased vastly. (McCarty, p.8) This is because as polarization causes preferences of the parties to diverge, the gap between pivotal voter preferences also increases. Such gridlock, as typified the early stages of healthcare, can sometimes only be defeated through loop holes. For example, the only way that healthcare reform was able to succeed was through a loop hole known as the budget reconciliation process. Reconciliation bills cannot be filibustered, and while such a process enabled the Democrats to pass healthcare, it is unnecessary, and only serves to decrease the legitimacy and authority of the government. Such a process is also likely to increase polarization, as the majority will likely lose more support in the minority, due to the using of a method that seems forceful.

Reduce Polarization to Improve Policy-Making

There are several ways that polarization could be reduced in order to improve the efficiency of policy-making. First, if income inequality is ignored, money must be removed from politics or replaced by time as the dominant medium. As Verba, Schlozman and Brady explain, “The gap in dollars between the richest and poorest is far wider than the gap in hours between the busiest and most leisured.” (Verba/Schlozman/Brady, p. 75) Campaign contributions and lobbying power should be limited, and active participation encouraged. This would likely create a less polarized environment. Second, income inequality should be directly addressed and reduced. This could be done with simple adjustments, such as increasing the minimum wage, or increasing the Earned Income Tax Credit. Also, though likely to be unpopular and unable to pass in the partisan environment, an increase in the progressive tax on the wealthiest 10% could possibly help reduce inequality and polarization. Finally, as I have already explained above, if polarization is not reduced, we must at least change the super-majority requirements of Congress to simple majority requirements, in order to prevent polarization from creating grid-lock and undesirable policy outcomes.

To sum it up, in the current American political climate, the combination of polarized parties and super-majority requirements has negative implications on policy-making and democracy in general. As we have seen, there has been an increase in filibusters and a decrease in the effectiveness of cloture votes. Furthermore, it is now clear that polarization is linked to a decrease in participation and an increase in income inequality. These features of polarization all show that, while strongly polarized parties may have at one point been effective, the current nature of polarization in U.S. politics prevents successful governance. When combined with rules such as the filibuster, polarization not only distorts the policy-making process but also fundamentally alters and warps the outcomes. In order to move forward in American Politics we must either mitigate the causes of and thereby reduce polarization, or we must fundamentally alter the super-majority requirements of Congress.


Fiorina, Morris P. Parties, Participation, and Representation in America: Old Theories Face New Realities.

McCarty, Nolan. The Policy Effects of Political Polarization. The Transformation of American Politics: Activist Government and the Rise of Conservatism. Edited by Paul Pierson and Theda Skocpol. Princeton University Press.

Patashnik, Erik M. (2008) Reforms at Risk: What Happens after Major Policy Changes are enacted? Princeton University Press.

Sinclair, Barbara. (2002) The “60-vote senate”: Strategies, Process and Outcomes. U.S. Senate   Exceptionalism. Edited by Bruce I. Oppenheimer. The Ohio State University Press.

Sydney Verba, Kay Lehman Schlozman, Henry E. Brady. (May-June 1997) The Big Tilt: Participatory Inequality in America. The Tocqueville Files. The American Prospect.

“Toward a More Responsible Two-Party System: A Report of the Committee on Political Parties” (1950). APSR, Vol. 44, No. 3, Part 2,Supplement. http://www.apsanet.org/~pop/APSA_Report.htm#REPORT [accessed 04/15/2010]


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