Every election cycle, journalists and campaign operatives fill the air with talk of momentum, ad buys, and viral moments. But what political science says about how voters decide is far more stable—and far less exciting. The core reality is that most elections are decided by a small set of durable forces, not by the daily churn of strategy. Understanding this gap between noise and substance is the first step to avoiding the Strategist’s Fallacy, a term coined by G. Elliott Morris in October 2025. The fallacy is the belief that voters hold coherent positions and match them to candidates like an entree off a menu. In truth, that describes almost no one.
The most important concept here is election fundamentals. These are the structural conditions that shape an election before any campaigning begins: the state of the economy, the incumbent party’s approval rating, and the general mood of the country. Morris’s two-input fundamentals model, which used only those basic conditions, forecast Harris at about 48 percent of the two-party vote in 2024; she got 49.3 percent. On conditions alone, Trump wins about nine times in ten. The three decisive states turned on 229,766 votes. That is not a story of brilliant ads or gaffes; it is a story of a close race where the fundamentals pointed one way, and the result landed near the prediction.
Why do fundamentals matter so much? Because voters do not think in left and right. The vast majority of people do not carry a coherent ideology. Converse found that about one voter in nine reasons ideologically, and Kinder and Kalmoe found that share has barely moved since. Morris puts it at 10 to 15 percent. That tiny slice is the only group that genuinely matches candidates to a mental menu of policy positions. Everyone else relies on shortcuts: party loyalty, group identity, and simple feelings about whether things are going well. Party loyalty, in particular, is the anchor. Most voters decide which party they belong to long before any campaign starts, and they rarely change. That means the actual election is not a battle for the whole electorate; it is a battle for a small sliver of people who are not firmly anchored.
That sliver is what we call persuadable voters or swing voters. They are not moderates versus progressives in the ideological sense. They are people who are less interested in policy details and more responsive to broad signals: which candidate feels safer, more familiar, or less risky. Campaign persuasion, however, has a hard ceiling. Across 49 field experiments, Kalla and Broockman’s best estimate of campaign persuasion in a general election is zero. That does not mean ads do nothing—they can mobilize people who already lean your way—but they rarely change minds. The idea that a clever message will flip a bloc of undecideds is mostly fantasy.
This is where journalists and strategists often go wrong. They mistake the daily noise—a debate line, a scandal, a viral clip—for a shift in the race. But if persuasion is near zero, then most of that noise is just that: noise. What actually moves the needle is a change in the fundamentals, like a sudden economic shock, or a candidate who manages to alter the basic perception of which party is more trustworthy on the top issue. Even then, the effect is slow and marginal.
There is also a second, subtler error. Broockman and Skovron found that legislators in both parties overestimate how conservative their constituents are. That means strategists often push candidates toward the ideological edge because they believe the base demands it, when in fact the base is less ideological than assumed. The WelcomePAC report Deciding to Win recommends a 2028 Democratic nominee willing to break with progressive advocacy groups—a recognition that primary dynamics and general election realities are different worlds.
The practical lesson is simple. For journalists, cover the fundamentals first: the economy, the incumbency, the partisan baseline. Treat campaign events as color, not as the main story. For strategists, accept that persuasion is mostly mobilization. Focus on turning out your known supporters and on not scaring off the small number of genuinely undecided voters. The election will be decided by the underlying conditions, not by the cleverest tweet. The noise is entertaining; the election-year grade fundamentals are real.