The Enigma of the Undecided Voter: Why We’re All Swing Voters

Every four years, as the air grows colder and the days shorter, America becomes captivated by a singular figure—an almost mythical creature in the political wilderness. This character, the undecided voter, is the star of countless news reports and campaign strategies. Imagine the suburban mom loading groceries into her car or the blue-collar worker sipping coffee at a diner, both seemingly unable to choose between candidates, their indecision portrayed as holding the fate of the country in a delicate balance.

But what if this image—one we've clung to for decades—is too narrow? What if, in truth, we are all undecided voters, and this notion, comforting in its simplicity, is misleading? What if the reality is far more complex, nuanced, and—here’s the key—more collective than we've been led to believe?

Researchers at Harvard's Institute for Quantitative Social Science (IQSS) have begun peeling back the layers of this long-held belief. The result is a startling conclusion: the firm line we’ve drawn between the “decided” and the “undecided” may not exist. In truth, every one of us is swaying, imperceptibly but undeniably, in response to the national mood, the political climate, and the stories that dominate the media. And here’s the thing—those voters in the middle, the ones we call “undecided,” are simply those most visibly affected by this swing.

The Real Swing

Let’s break this down. The so-called undecided voters aren’t a different breed; they aren’t standing on a fence waiting to be convinced. No, these are voters who sit in the middle of the political spectrum—near the threshold where, when the political winds shift, their votes become more visibly in play. But that doesn’t mean they’re indecisive. It means they’re more likely to change their vote when the electorate as a whole shifts. They move with the same tides that sway even the most loyal partisans. The difference is that their position makes their movements more noticeable.

What this means is that campaigning specifically for the “undecided” isn’t quite the point. The entire country is swaying, and the swings we see in these middle-ground voters are simply the visible reflection of larger movements in the electorate. You could look at the most solidly Democratic or Republican areas and see that even those voters are shifting—just in less obvious ways. The key difference? The ones in the middle, on that threshold, are the ones most likely to change their votes, depending on how hard the swing hits.

The Great Unraveling of Voter Behavior

In 2016, a heated presidential race was unfolding. The polls were tight, and news channels were frantically searching for that mythical "undecided voter." It was during this time that Ryan Enos, (https://www.gov.harvard.edu/directory/ryan-d-enos/) a political scientist at Harvard, began to ask a different question. What if the real story wasn’t about the few who were genuinely

undecided, but about the subtle shifts happening in the hearts and minds of even the most loyal partisans?

Enos’s groundbreaking research on political segregation, particularly as explored in his book The Space Between Us: Social Geography and Politics, examined this idea. He found that even those voters who cast their ballots red or blue every four years aren’t as immovable as they seem. Take, for instance, the lifelong Democrat who never hesitates to pull the lever for their party or the staunch Republican whose loyalty never wavers. While these voters may not switch parties, they aren’t impervious to the national climate. The latest economic downturn, the rise of a populist movement, or even a news cycle dominated by a political scandal can subtly alter how they feel about their candidate—without ever changing their vote. Like boats in the same ocean, even those anchored firmly still drift with the tide.

The Emotional Tug-of-War

As Election Day nears, even the most steadfast partisans feel the push and pull of competing emotions. Jennifer Lerner, a professor at Harvard’s Kennedy School, delves into the psychology behind these subtle movements. Her research on emotion and decision-making shows that what we feel can be just as important as what we think when it comes to

voting. (https://scholar.harvard.edu/files/jenniferlerner/files/emotion_and_decision_making.pdf).

Picture this: the loyal Democrat who’s been with the party for decades starts to waver, not in their ideology, but in their enthusiasm. Maybe it’s a story in the news, or the constant barrage of negative ads, but something begins to shift. Lerner’s work explains how emotions can create internal conflict, even for voters who believe they’ve made up their minds. The same thing happens to the voter in the middle—the difference is that their vote may actually change.

Apathy and the Swinging Voter

Even disengaged voters – those who don’t follow politics closely – are part of this dynamic.These are the people who don’t watch debates, don’t follow candidates on Twitter, and may not even vote every year. You might think they’re immune to the national conversation.

But Harvard researcher Matthew Baum (https://scholar.harvard.edu/mbaum/publications/publication-topic-area/media) and Adam Berinsky from MIT’s Department of Political Science (https://scholar.harvard.edu/mbaum/publications/publication-topic-area/media) have found the opposite to be true. In their work on the study of political behavior, media influence, and public opinion, they discovered that these voters, far from being immune to political winds, are often more influenced by them. Apathy, it turns out, doesn’t act as a shield against the national mood. In fact, it can amplify it. A disengaged voter may not dive into policy debates, but they are still part of the broader cultural and social currents shaping the country. Their decision to vote—or not—can be swayed by what’s happening around them, perhaps even more so than a dedicated partisan. Like everyone else, they swing, but in ways that are less obvious.

The Media’s Role in the Swing

Here’s where the story takes another twist. Yochai

Benkler, (https://hls.harvard.edu/faculty/yochai-benkler/) a media scholar at Harvard, along with his co-authors Robert Faris (https://cyber.harvard.edu/people/rfaris) and Hal Roberts, (https://cyber.harvard.edu/people/hroberts) argue in their book Network Propaganda: Manipulation, Disinformation, and Radicalization in American Politics that the media’s focus on the undecided voter obscures the larger picture. The media portrays undecideds as critical while ignoring the fact that the whole electorate is in motion. This fixation misses the reality that all voters, from the most partisan to the least engaged, are affected by the same national conversations. The media’s narrative of a static electorate, disrupted only by a few undecided voters, misses the reality: the entire country is constantly in motion. It’s not just a few fence- sitters who are swaying. We all are.

A New Understanding of Voter Behavior

This brings us back to the broader insights from IQSS, particularly to Gary King, the institute’s director. Prof. King’s work (https://gking.harvard.edu) reveals that voting behavior is shaped by the social environment we’re all swimming in. No one is making decisions in isolation. The conversations we have, the news we consume, the subtle cues we pick up from those around us—they all influence us, even if we don’t notice. And it’s not just the undecided voters at the margins. It’s everyone.

The implication here is profound. Campaigns that focus solely on undecided voters are missing the real battleground. The truth is, the real battleground is the entire electorate, constantly swaying in unison with the national conversation.

The Swing of Things

So, what does this mean as we head toward another election cycle? It means the myth of the undecided voter only tells part of the story. If you really want to understand what’s happening, you have to look at the bigger picture. The swings in the middle are just a reflection of the swings happening across the electorate. We’re all part of this collective movement, this shifting landscape. And that’s the real story.