After the World Wars American public discourse looks to me like it declined very clearly.
Presidential debates shouldn’t suffer from e.g. improvements in access creating the false impression of reduced elite quality. Compare the Nixon-Kennedy debate, the Ford-Carter debate, and the Trump-Biden debate. N-K were dishonest but trying to fool voters who were trying to track arguments and figure out what was going on. I recently watched Nixon’s Checkers speech too; it’s famous as an innovative subject-changing appeal to emotion but to my contemporary ears the main thing that stood out was that most of the speech was an appeal to reason that would be tedious to someone who wasn’t thinking explicitly in terms of argument and evidential value.
Back to debates. F-C was sound bites designed to give the superficial impression of argument. T-B was just trading personal insults. I watched the unofficial version on Rumble where RFK Jr inserted himself and there was a strong contrast between the officially included debaters and RFK Jr, who just … answered the questions, like it was still the ’90s.
On the object level this seems unobjectionable and true. But the example of criminal defense isn’t just a good one for providing examples, but an unusually appealing one. With motivated prosecutors and proceduralized courts, cornering liars can be sufficient for making progress past the lie. In other circumstances, this can be much less true, e.g. when liars are trying to signal bad faith rather than good.
What’s needed for many circumstances of public life is some strategy for how good faith ought to confront brazen bad faith, as right now such encounters frequently end with both sides feeling like they won. The first step is for more good-faith players to discuss the problem.