Fig. 4

Evolution of key 2016–2024 election issues over time. We plot topic prevalence (measured via mean topic probability) over presidential elections from 1952–2012. Topics focus on 9 key issue areas, which represent the union of the top 3 issues from each of the most recent 3 presidential elections, 2016–2024, plus two additional topics (taxation and crime) that reflect remaining issues among top-3 issue areas in terms of advertiser attention. For presentation, we partition the issues into three plots corresponding to economic policy and social welfare, security and international affairs, and law and the courts. Error ribbons represent 90% credible intervals computed via the standard highest density interval method.