Do debates matter? A million thoughtful commentators used to tell you that they did not, right up until the moment Joe Biden’s face melted off his skull during the first 2024 debate like the bespectacled Nazi at the end of Raiders of the Lost Ark. (“Don’t look at the livestream, Marion!”) So for 2024, at least, I think it’s fair to say that debates matter, especially when there’s only one for the final presidential match-up between Donald Trump and Kamala Harris. And in terms of what each...