Professor Georgia Kernell in the News! Forbes: This Is The Reason American Politics Are So Polarized

Forbes – Kevin Anderton

In recent years, the American political arena has become increasingly polarized. Story after story, day after day, the situation only seems to be getting worse. The result is that the majority of Americans are now going through some kind of political fatigue where we would rather turn off the news and social media rather than take part in another “discussion.”

How did it come to this when polling shows that most Americans hold fairly moderate views? Why are the two major political parties moving to extreme left and right positions? Will this stop at some point or will it get worse? Many of us have asked these questions but now it seems that Vicky Chuqiao Yang, a complexity postdoctoral fellow from the Santa Fe Institute and a team of researchers from Northwestern University and UCLA may have some answers for us.

Yang and her team have created a dynamic model that was able to predict the polarization of the parties and has been tested against 150 years-worth of data. The model, which was detailed in the SIAM Review, shows that the polarization is not, as one might think because Americans are taking more extreme views but because the parties are using political strategy to gain votes.

“It’s intuitive to think the parties are drifting because voters are holding more extreme views on policies and disagreeing with each other more,” Yang said. “It feels true because we see a lot of antipathy in the news and social media, but the true picture of polarization among the population is actually a lot more nuanced than people think.”

The Model

Previous models have tried to predict the behavior of the Democrats and Republicans and many have done so by assuming a two-party competition on a one-dimensional idealogy space. In addition, they assume that voters will vote for whoever is closest to their ideals and parties will adjust their views to maximize votes. However, if this were the case it would be in a party’s best interest to retain moderate views as that would ensure the most votes. Why then is this not the case?

The problem is that previous models fail to take in proper empirical data and do not account for voters picking candidates that are “good enough” without obsessing over details. Furthermore, they do not take into account misinformation, missing information, decision fatigue and other things that can stand in the way of an optimal decision.

Yang and her team, which includes Daniel Abrams, Associate Professor of Engineering Sciences and Applied Mathematics at Northwestern University, Adilson Motter, Charles E. and Emma H. Morrison Professor of Physics at Northwestern University, and Georgia Kernell, Assistant Professor in the Departments of Communication and Political Science at UCLA, created a model that works a little differently. They took all of those factors into account along with 150 years-worth of U.S. Congressional voting data from the American Nation Election Study. They then compiled all of this information using complex mathematical formulas and came out with something that explains why politicians are becoming more polarized.

How it Works

First, we must understand the shape of the American political system and how parties shape themselves to function within it. The graphic below sheds some light on this subject.


The graph above is a simplified version what was used in the new model. Along the x-axis, we see the political spectrum from Liberal (left) to Conservative (right). The y-axis shows the number of voters as it relates to x. The grey area represents the voter pool and it shows that most voters have moderate views and only a few have extreme left or right views. The views of a political party are represented in the red area. This area can move left or right depending on the changing views of the party. In addition, the area can widen to become more inclusive with its views or narrow to become less inclusive. The area where red and grey overlap shows the number of likely voters that will support the party’s platform. Voters outside this area will either vote for another candidate or not vote at all.

Typically, when there are two parties in this system, they will settle some distance apart in order to win most votes. Over time the two-party system finds an equilibrium with one on the left and one on the right. Sometimes these parties will move farther apart and sometimes they can be close enough together to overlap.

If the inclusiveness (the width of the red area) of the parties was to decrease the center would be left open and which means more voters should abstain from voting. However, in recent years both the Democrats and Republicans have been moving away from the center and narrowing their views. This has left a large number of moderate voters in the middle but many of them have still been voting. Yang’s new model accounts for this by including a concept known as “satisficing” where people vote for a candidate that is “good enough” rather than the most qualified. The result is a large number of voters in the middle are continuing to vote but are not happy with either candidate.

With this information and a lot more the model created by Yang and her team have been able to predict the movement of the parties away from the center.


Here we can see that the parties have been moving away from the center and that the new model is able to predict this behavior with a fair amount of accuracy. The greyline shows the model predictions and the red and blue areas show the actual results based on Congressional voting data.

Yang’s model is one of the first steps in understanding what is happening in American politics. With information like this, we might be able to explain why parties are losing votes when they try to move to the center. The reason most likely has to do with political theater. As a party softens their position they become open to attack from the opposition. The result is that the other side looks tough and resolute in their beliefs and the softening side looks weak and appears to be pandering to get votes. The result is the creation of an “us or them” feeling to American politics. This is why in 2020 it feels like we are all taking sides in tribal warfare.


My two cents

The current presidential election seems to be a good example of parties that have gone to extremes. Especially, when we look at the primary season. For a while, it looked like we were going to have too extreme candidates. Right now, President Trump seems to be keeping with the strategy of a narrow rightwing platform. However, unless I am mistaken, Joe Biden seems to have moved more toward the center to try and get as many votes as possible. I have no idea which strategy will win this time around nor will I try and direct anyone’s vote. We will just have to wait and see what happens.