CBS News poll analysis: Is there an enthusiasm gap between Trump and Biden?

Campaign strategists and pollsters often talk about an "enthusiasm gap" between parties, suggesting one side's supporters are more enthusiastic about voting than the other's. Some, including President Trump, have touted a 2020 enthusiasm advantage for Republicans. Is that really the case and, either way, what can it tell us about this year's campaign?

The first thing to know is that surveys measure enthusiasm in a variety of ways, and the way a question is asked can produce different results. Some ask about excitement about a particular candidate, while others ask...