In Joe Biden’s first presidential debate with Trump, he made exactly the same mistake that Hilary Clinton made in 2016. And he will make the same mistake in the next debate.
He will allow Trump to continuously interrupt him and change the subject, and he will respond to the new unrelated subjects that Trump will interject. He will not tell Trump firmly to stop interrupting. He will not point out that Trump is changing the subject in order to avoid addressing the subject in the question.
Likewise, the moderators will make the same mistake that they made in the 2016 presidential debates and repeated in the first Biden-Trump debate. They will allow Trump to interrupt and change the subject, and will not establish a procedure to mute each candidate’s microphone when the opponent is answering a question.
On the positive side, at least it is reassuring to know that we can rely on both Joe Biden’s and the moderators' consistency.