"What-If?" Election-Night Simulator by 538/ABC News

Pre-election predictive models have become mainstays of political journalism in America over the last two decades. The predictions from models published by media outlets such as 538 and The Economist, as well as polling averages from the New York Times, Washington Post, and others, are echoed in other outlets and on social media, and form the basis of a collective understanding of the state of the race for a wide array of elections. But pre-election forecasts and averages have one major shortcoming: They cease to be relevant precisely when audiences are most tuned in to the election, on election night itself.

This problem inspired 538 to build an interactive project that enables users to update our presidential pre-election forecast using actual results as they come out on election night, allowing us to continue to help readers understand the election all the way to the final vote counts. The interactive also lets readers explore the potential paths the election may take ahead of Election Day, better grounding them in the uncertainty inherent in public opinion polls and election prediction.

The interactive also powered a dashboard for ABC News, which owns 538, which was used during the company's election-night television broadcast coverage. This made ABC News the only media outlet to air live probabilistic forecasts during broadcast based on analysis of election returns from the network's anchors and decision desk. This provided key context for audiences on what the returns ultimately meant. Once it was obvious that Donald Trump was going to win Florida and North Carolina (two fast-counting states), for example, anchors were able to tell readers that his probability of winning the Electoral College had risen to around 80 percent. These odds were updated and projections relayed to audiences throughout the night.

Our hypothetical election simulator offers readers of political news an exciting angle into understanding how American presidential elections work, and seeing visually how the indicators they see in the news might not translate into reality. The interactive also offers a way for readers to engage with election results on election night, when anecdotes and incomplete data otherwise confuse audiences into the wee hours of the morning (or, as in the case of the 2020 race, days later).