Probabilistic Quantification of Swing State Importance in the 2024 Electoral College

The winner of the United States presidential election is determined by which candidate is the first to reach 270 electoral votes. The winning candidate in most states can be reliably predicted in the months leading up to the election from historical trends and polling data. The remaining states are referred to as “battleground states” or “swing states”; these are the states which typically end up deciding the electoral winner. Campaigns are known to funnel a sizable portion of their finite resources (money, time, rallies, advertising, etc.) to these swing states in the months leading up to the election. Yet, to this point in time, very few mathematical procedures have been developed to quantify the influence of each swing state to a candidate’s election odds. In this paper, we focus on the seven tightest states for the 2024 presidential election and use conditional probabilities to quantify the importance each swing state has to each candidate’s probability of winning the electoral college. This methodology has the potential to serve as a guide for campaigns in the future, helping them determine how to allocate their limited amounts of time and resources to maximize their odds of winning the campaign.