A House Divided: Is Congress Fueling or Reflecting Polarization in the US?

By Benji Hoff
Art by Rhea Da Costa, Resident Artist

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If you ask any politically aware person about the state of American politics today, they will likely characterize it with one word: polarization. A person’s views on today’s most prominent political issues—such as abortion, gun control, tax brackets, immigration policy, and more—can often be predicted based on their views on any single one of these issues. According to a study by Pew Research in 2016, 66% of Republicans agree with their party’s positions on abortion, and 80% on gun policy (“Partisanship and Political Animosity” 2016). On the other side of the aisle, 81% of Democrats agree with their party’s economic policies and 77% back the party platform on immigration (“Partisanship and Political Animosity” 2016). These numbers demonstrate the general lack of deviation from the party platform. Political scientists are split on the origin of this trend. Does polarization come from the bottom up as people become more ideologically distant from one another and surround themselves with like-minded individuals? Or does the partisan nature of our legislature trickle down to ordinary citizens and push them farther apart? 

The trends demonstrated in Congress certainly suggest the latter. Another Pew Research report has tracked polarization in Congress since the 92nd Congress in 1971 (Desilver 2022). The report uses a method that records members’ roll call votes to track the ideological divisions over time. A roll call vote is a simple “yea” or “nay” vote on a particular motion in the House or Senate. A member’s votes will reflect their policy preferences, making this a viable method to compare different Congresses to each other regardless of the relative political climate in each one. 

The report places lawmakers on a left-right spectrum from -1 being the most liberal to 1 being the most conservative. Since the 92nd Congress, both parties have strayed further from the ideological center, but Republicans have moved farther. Democrats in the House have moved from an ideological score of -.31 to -.38, representing a moderate increase (Desilver 2022). House Republicans have moved from .25 to .51, doubling their ideological score and representing a starker move toward the extreme (Desilver 2022). Over the past 50 years, both parties have become more ideologically cohesive. There is much less voting across party lines, and like the average citizen, a member’s views on one issue will likely predict their views on any other issue. In the 92nd Congress, there were more than 160 representatives that could be characterized as moderate; now, there are just over 20 (Desilver 2022). 

These stats do not confirm the origin of polarization. What they do show is that Congress has grown more divided over time just as American citizens have. Furthermore, Congress exhibits the same partisan animosity found in every-day political discourse. In addition to the rarity of voting across party lines, lawmakers often refuse to collaborate with members of the opposite party. This polarization in Congress results from the structural design of our government in which congressional majorities dominate the agenda, pushing their own policies and blocking those of the opposition. The House Rules Committee is the source of power in this regard. The Rules Committee is controlled by the Speaker of the House, who is a member of the majority party. The Speaker decides who is appointed to the Rules Committee, and if members do not follow the Speaker’s agenda, they will be replaced with new appointees. The Rules Committee is powerful because it unilaterally determines the agenda in Congress, with the exception of some jointly supported bills that are discharged from committee. Which bills are considered on the floor and the terms of floor debate are among two of the major legislative procedures that are controlled by the Rules Committee. 

When House majorities change, there tends to be a flurry of legislation passed by the majority party and heavy use of the Rules Committee to snuff out the other party’s agenda. The new majority wants to establish control and dominance over the minority party. This was the case to an extreme degree in the 104th Congress. In 1994, the Republicans swept the elections, gaining control of both the House and the Senate. This marked the end of a 40-year drought in the House, and the Republicans were eager to take control. House Speaker Newt Gingrich adopted a highly confrontational approach to the Republicans’ newfound power (Fenno 1997). He and the rest of the Republican majority tried to push through as much legislation as possible, block any Democratic legislation, and overall asserted their authority over the Democratic minority. A conflict over the Republicans’ proposed budget plan resulted in two government shutdowns, and President Clinton vetoed Republican legislation on spending and tax cuts. Being out of power for so long meant a significant lack of experience in leading as well as an inability to craft bills that would also be supported by the Democratic minority. The uncompromising strategy of the Republicans led to a stronger divide in the House, and the handling of their majority power was viewed by many as ineffective. 

Political incentives also drive legislators to high levels of partisanship. In 1974, David Mayhew published his seminal work Congress: The Electoral Connection, in which he characterized Congress members as “single-minded seekers of reelection” (Mayhew 1974). Mayhew applied the rational choice theory of economics to Congress, which states that all humans make rational choices that provide them with the greatest benefit (Ganti 2022). He argued that all electoral activity taken by Congress members is done with the hope of reelection, because without reelection no other political goals can be achieved. While members do try to pass legislation that benefits their constituents and answers their needs, this is often selfishly motivated. If voters see representatives as adequately fulfilling their policy goals and needs, they will vote for them again. Reelection serves to further polarize Congress because breaking from the party line on Capitol Hill will upset the constituency on the ground. Additionally, straying too far from the party platform runs the risk of a challenge within one’s own party. Falling in line with the partisan platform is ultimately best for a Congress member’s hopes for reelection.

The importance of roll call voting is relevant again, as it is an easy instrument for members to signal their ideologies to both their constituents as well as their political opponents. An easy way to gain support from your voting base is to differentiate yourself from the opposite party. Roll call votes provide a clear and understandable record of a Congress member’s ideological platform. This combination of procedural and political factors keeps Congress—and by extension, the country—divided.

Of course, Congress is not the only cause of polarization. Geographical sorting also has some effect, but it is usually overstated in the discourse surrounding polarization. Sorting refers to the phenomenon of people intentionally moving into communities that are comprised of politically like-minded individuals. Political scientist Bill Bishop articulated this theory in his 2008 book The Big Sort, positing that people actively prefer to be surrounded by voices similar to their own (Bishop 2008). More recent research has revealed two major holes in this theory. First is that most people are financially restricted from living wherever they want. No matter how liberal a person identifies, most can not afford to live in the most liberal parts of the country, which are large, dense cities with exorbitant rent. Secondly, Americans tend to move frequenty, so data is not always accurate as population distributions shuffle around (Martin and Webster 2018). It is also counterproductive to blame citizens’ living preferences for polarization when oftentimes economic and social policy affects where someone chooses to live. 

Many may point to gerrymandering as a cause of polarization. Safe districts—districts that are reliably either Democratic or Republican—certainly disincentivize working across the aisle, but the reason for this goes back to reelection goals. Why would a representative from a safe district risk their reelection prospects by collaborating with a despised political rival? The main problem with the gerrymandering explanation is that the US Senate can not be gerrymandered because each state elects two Senators at large, regardless of population. The Senate demonstrates the same patterns of ideological division that the House does, so gerrymandering can not be the primary cause. 

Media is also often blamed for polarization, but news outlets are best viewed as amplifiers of extreme politics, not creators. Most politically engaged people recognize the political leanings of different news sources and try to balance their media intake accordingly. Those who exclusively watch CNN or FOX likely already have solidified views and are seeking confirmation. Media companies are businesses, so they may value ratings over truth or sincerity. It makes sense for them to appeal strongly to one demographic as opposed to appealing to both sides of the political spectrum. Hence, the polarization of the media is an effect—not the source—of nationwide polarization as networks attempt to please specific political groups.

Overall, Congress’s effect on polarization is largely understated and often excluded from the discourse on the subject. Perhaps this is because the processes and procedures of Congress are an elusive, complex subject that many people do not have the time or interest to delve into. It is much easier to consume mass media, browse news headlines, and then share partially-formed views on social media. However, easier does not mean better. This surface-level engagement with politics is certainly a factor in the intensely polarized political climate of today. Maybe a more nuanced understanding and broader discussion of our governmental structure could contribute to a decline in polarization. Voters would be more informed, putting more pressure on lawmakers to work together towards productive goals rather than seeking to widen the political aisle. An informed, educated public can help uproot polarization on the ground, but it is also crucial to understand our government and how it works to divide us from the top down. 

Benji Hoff is a sophomore from Stamford, Connecticut. He is majoring in philosophy, politics, and law and plans to attend law school after graduating. Benji was a part of the Source Project at BU, a year-long research program for first-year students. In the Source Project’s History and Capitalism stream, he studied many contemporary political theorists and philosophers, culminating in a research paper on Jewish and capitalist ideology. In his free time, Benji loves to play and watch sports; he is a diehard Mets fan! He also plays guitar and is an avid listener of classic rock and roll music.


Bishop, Bill. 2008. The Big Sort. Boston, MA: Houghton Mifflin. 

Desilver, Drew. 2022. “The Polarization in Today’s Congress Has Roots That Go Back Decades.” Pew Research Center, March 10. www.pewresearch.org/fact-tank/2022/03/10/the-polarization-in-todays-congress-has-roots-that-go-back-decades/.

Fenno, Richard. 1997. Learning to Govern: An Institutional View of the 104th Congress. Washington, DC: Brookings Institution Press. 

Ganti, Akhilesh. 2022. “Rational Choice Theory: What it is in Economics, With Examples.” Investopedia, May 24. www.investopedia.com/terms/r/rational-choice-theory.asp.

Huder, Josh. “It’s Congress’s Fault: How Congress Polarizes America.” The Government Affairs Institute, Georgetown University. gai.georgetown.edu/its-congresss-fault-how-congress-polarizes-america/.

“Majority Changes in the House of Representatives, 1856 to Present.” History, Art, and Archives: United States House of Representatives. history.house.gov/Institution/Majority-Changes/Majority-Changes/.

Martin, Greg, and Steven Webster. 2018. “The Real Culprit Behind Geographic Polarization.” The Atlantic, November 26. www.theatlantic.com/ideas/archive/2018/11/why-are-americans-so-geographically-polarized/575881/.

Mayhew, David. 2004. Congress: The Electoral Connection. New Haven, CT: Yale University Press, original 1974.

“Partisanship and Political Animosity in 2016.” 2016. Pew Research Center, June 22. www.pewresearch.org/politics/2016/06/22/5-views-of-parties-positions-on-issues-ideologies/.