Five Years of Studying U.S. Congress: What Remains?

A few days ago, my dissertation, titled “On the Record: Understanding a Century of Congressional Lawmaking through Speech and Vote Behavior” was published via Linköping University Press.¹ As I am writing these lines, it is still about four weeks until I have to defend this thesis. I will have to answer what I have been doing these past five years, how I have been doing this, and what its results mean.

And these are very relevant questions. What exactly is it that I have been doing in these past five years? What did we learn? How did I contribute to the scientific field? It is a cold September night, and in trying to find some sleep, I realized that the best preparation towards my defense may not be to simply re-read the entire thing, but to actually reflect on it. Answer questions that others possibly also have. In turn, I may be able to myself better understand what it is that I have been doing, and what it means.

I don’t know how long these reflections will become, or how structured these articles are going to become. But what I want to do with this and any following articles is three things: (1) explain to myself what I have been doing the past five years; (2) explain to others why it is important; and (3) answer questions colleagues and friends are posing towards me or that emerge while writing.

Lawmaking in U.S. Congress

Let me start with explaining what I have been doing. In essence, I study how the U.S. is making its laws, and how the interactions of various representatives can sometimes lead to unexpected policy outcomes. That’s it. This is the “Tweet my thesis”-version of my thesis.

But there is more, obviously. I take a close look at episodes in which lawmaking appears to diverge from its regular paths. I am not looking at episodes in which lawmaking works as it is supposed to. Instead, I look at crises, disagreement, and when laws get passed or rejected against all odds.

The core of my thesis consists of three distinct “irregularities,” if you so wish, of U.S. Congressional lawmaking. In one paper, I focus on what we mostly know under the term “neoliberal revolution.” In another one, I focus on the increasing party polarization, and try to understand how it plays out on the level of policy preferences. And, lastly, in a third paper I focus on dissent and breaking ranks by representatives during votes.

So, essentially, the correct answer to “What have I been doing the past five years?” would be: “To understand what happens when customs and regularities break down. What do legislators do when a crisis happens?”

How do Crises Help Understand Peacetime?

But how can crises help us understand how a legislative works in general? Are crises not defined to be states of exception?² The answer to this question is threefold.

First, “man is an animal of difference,”³ as Georg Simmel has once put it in his essay “The Metropolis and Mental Life” (1903). In simple terms, this means that it is easier for us to understand how society works by looking at the “bumps” of history. Crises enable a comparison that is much harder to find in peacetime, because crises are precisely those times in which “[e]stablished cultural ends are jettisoned with apparent ease” [@Swidler1986, p. 278]. This implies two things: first, there must have been somewhat stable cultural ends which can actually get “jettisoned.” Second, by comparing how social indicators change in this time of crisis, this gives us a measure of what changed, and in what direction.

This points to the second part of the answer to our question. Unlike in physics, there is no “absolute zero” — no baseline — in society. That means: when we attempt to take measurements of society, we often cannot tare them against some known baseline. The closest concept of a “baseline” we have would probably be “normality,” but this is a curious concept. We all intrinsically understand when something seems normal, but it is almost impossible to define.⁴ The same holds true for legislative processes. What exactly makes lawmaking “normal”? This is why shedding a light onto “abnormal” times can help. When we cannot take absolute measurements and have no way of knowing what a normal procedure looks like in our measurements, sudden changes can help us infer how the process might’ve worked in normal times. Now that I am writing this, I realize that essentially all of my colleagues who have already defended did the same thing. In all of their theses and papers, you will find instances of looking at abnormal events or phenomena in order to understand society.⁵

The third part of the answer is somewhat more mundane and innately practical: The U.S. is, as of today, one of the oldest continuous democracies in existence. And this means that “understanding Congressional lawmaking” involves making sense of the figurative “metric ton of data”⁶ that Congress has produced. The longest continuous stretch of time which is covered by the various data sources spans significantly more than a century (116 years). Amid this flood of data, it is difficult to find anchor points, and as such, choosing well-known episodes of turmoil is a safe strategy to be able to get a hold of the phenomenon of interest.

So, What Did We Learn?

This leads to a final question (for today, at least): What did I actually show in my dissertation? As is the case with compilation theses, as opposed to monographs, the results are fractured; divided into three papers that comprise the core of my thesis.

In the first paper, I look at the “neoliberal revolution” under president Ronald Reagan in the 1980s. I wanted to understand why U.S. Congress would suddenly shift gears to pass laws that would abrogate decades of Keynesian economics and replace them with a new — and at that point essentially still unproven — idea. Mind you, the idea of “neoliberalism” was very young even in the 1980s. However, it had been taught at universities already, and as such has been passed on to the highly educated, who would then continue to become representatives in U.S. Congress.

Much of the literature on neoliberalism in the U.S. focuses on the presidency, and as such the role of Congress has been culpably neglected. What this paper can show is that we can see a sudden uptick in saliency of Congressional economic speech during the especially disastrous 1970s. This appears to imply that Reagan received help not just from his party, but also from many highly educated Democrats. Many appeared to agree with him on economical grounds, since the ideas of tax cuts and budget reductions likely resonated with what they learned in university.⁷ This might furthermore imply that at least in the 1980s the U.S. government worked the way it was intended — with presidency and U.S. Congress in a mutual dependency.

Moving on to the second paper in my thesis, I focus on the phenomenon of polarization. Much of the political science literature since the 1980s has detected a sharp increase in party polarization in the U.S. What this means is that the two parties move apart, rendering bipartisan agreements on legislative initiatives less and less likely. Over the years, political scientists have linked this to many ails in the U.S. legislative. This starts at frequent stalemates that may lead to government shutdowns, to a general hostile atmosphere, where politicians are less interested in mutual understanding, and more in personal gains.

However, most of the studies analyzing polarization rely on vote results. But vote results can only tell us how someone has voted, but not why.⁸ This means that these studies tell us little about what may drive this increase in polarization. Indeed, the discussion on the causes of polarization are one of the most intense debates in political science I have witnessed. What I do in my paper is look at a neglected source of information in this realm: speeches. What the paper can show is that, as we zoom in on individual issues, polarizing trends disappear. While polarization still occurs when taking all speeches into account, this implies that polarization is a macro-phenomenon that may not solely be caused by partisan identities and extreme politicians pulling the parties apart. What might be at play here are institutional pressures that produce polarizing trends against the representatives’ preferences.

Indeed, what has received surprisingly little quantitative attention are the institutions that dominate Congressional life — parties, whips, and committees. There are great qualitative works, do not misunderstand me,⁹ but what is lacking is a quantitative understanding of how these institutions interact with lawmaking processes. We know that parties have a huge impact on which legislation is being passed, and that committees decide on life and death of bills. But we know little about how they do so.

This is what I look at in my third paper. Here, I focus on what happens when representatives disagree with their party. How free, or capable, are they to break ranks with their own party? This is a surprisingly hard question to answer, non the least because what a party “is” is epistemologically a very difficult question. In fact, political scientist Keith Krehbiel nailed the problem when he asked “Where’s the party?”¹⁰

In order to at least approximate a measurement for the power of parties to direct their representatives in their votes, I look at how well the preferences of individual representatives align with their party. Based on this, I check whether a misalignment may make them more likely to vote against their own party. To my surprise, the results show a weird trend: parties are rapidly losing power over their representatives since the early 1990s. Today, if a representative wants to break ranks, they can simply do so. This was much harder in the 1950s or 1960s. This seems to imply that what happened is a strong alignment of parties and representatives in their preferences.

Taken together, these results paint a picture of how Congressional legislation worked and changed over more than a century. While I am unable to say much in detail about the period before the end of World War II, since the data is deteriorating quickly as we move into the past, afterwards some clear patterns emerge. First, it appears that the 1940s, 1950s, and 1960s are a very stable period for U.S. Congress. Now, politically ground shaking events took place at the same time, such as the civil rights movements. What I want to express is that the Congressional machinery worked like a well-oiled motor. In the 1970s, as the U.S. economy was devastated by a flurry of crises, the outlook changed. The presidency of Ronald Reagan shifted Congressional priorities. However, one cannot say that this necessarily cemented all the trends we can see in Congress. Many of the detrimental trends scientists have found have started to pick up speed only since the early 1990s, and I believe that representatives such as Newt Gingrich with his “Contract with America” may have done more long-term harm than Reagan.

All of this leaves us with a legislative system that, in 2025, is barely able to withstand presidential authoritarian pressure and folds almost daily. Daniel Ziblatt and Steven Levitsky have argued in their 2018 book “How Democracies Die” that the pivotal point at which the U.S. political system took a nosedive was when the parties stopped working as gatekeepers. This is certainly a possibility. What remains is that, by focusing on three moments of crisis in the Congressional system, we can see that what happens today is a result of a progressive degradation of parties and representative culture alike.

Open Questions and Further Threads

All of this leads to more questions. Based on my results, how might we conceptualize the second Trump presidency? Is this also a form of crisis? Also, I did not talk about my methods here, yet. Additionally, as I am talking about my thesis with friends and colleagues, more questions emerge. Just today, the question popped up: Which parts did I enjoy writing, and which ones didn’t I? This has led to an interesting discovery of a trajectory of turning from a theory-driven researcher towards a more methods-based researcher.

There are many open questions, and as I read through, and reflect on my work of the past five years, more will emerge. I will try to do my best to write these down; partly as research notes, partly as targeted articles, but always with the intention to publish them here, which will greatly increase their readability, and motivate me to think further.

The coming weeks will probably be dedicated exclusively to this one, big, white building on the banks of the Potomac River, and the people who fill it with life.

¹ Erz, H. (2025). On the Record: Understanding a Century of Congressional Lawmaking through Speech and Vote Behavior [PhD Thesis, Linköping University]. https://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-217773
² See Koselleck, R., & Richter, M. (2006). Crisis. Journal of the History of Ideas, 67(2), 357–400.
³ Full quote: “Der Mensch ist ein Unterschiedswesen, d. h., sein Bewußtsein wird durch den Unterschied des augenblicklichen Eindrucks gegen den vorhergehenden angeregt” (transl.: “Man is an animal of difference, i.e., his mind is stimulated by the difference between his current and previous impression”).
⁴ To state the obvious comparison, “Normalcy is like porn: we know it when we see it.”
⁵ This might just be a variant of survivorship bias, because of course I have not read all of my predecessors’ theses completely. But of those which I did read and understood — Rodrigo Martínez Peña (link), Miriam Hurtado Bodell (link), and Anastasia Menshikova (link) — all of them looked at irregularities of society to understand its regularities.
⁶ Completely unnecessary information: While writing this sentence I was interested in knowing why the phrase “metric ton” has this ring of “a very large amount,” and according to a quick internet search, it’s because there are two definitions of tonnes. The U.S. defines a ton as 2,000 pounds, but the metric ton actually weighs a bit more, with ~2,204lbs.
⁷ Related to this, Elizabeth Popp Berman has written a highly instructive book on the Democrats adopting a very technical language during that time, called “Thinking like an economist: how efficiency replaced equality in U.S. public policy.”
⁸ Incidentally, this was the point at which I realized that a somewhat implicit question in a lot of quantitative text analysis is: do you look at the form of text, or its contents? I will go into this further.
⁹ The “classics” are certainly Richard Fenno’s “Congressmen in Committees” (1973); Gary Cox’s and Mathew McCubbins’s “Setting the Agenda” (2005); and Lawrence Evans’s “The Whips” (2018).
¹⁰ Krehbiel, K. (1993). Where’s the Party? British Journal of Political Science, 23(2), 235–266.