I played Trump in Clinton’s debate prep. Here’s what Biden can expect.

On any given day, Trump decides whether he wants to speak, and where and when. What to talk about. Whether to take questions, and if so, from whom. How long to let reporters speak before interrupting and berating them. And he decides when he has had enough.

That’s not a debate, and it leaves him ill-equipped for one. Because the 2016 Trump with the clear message, honed attack and efficient defense mechanism has given way to something else: a politician who cannot articulate his vision for a second term. On offense, he’s a mess; he can’t settle on an overarching attack on Biden, or even two. Even his already-overrated nicknaming skills have all but failed him. As for defense, his existence now entirely involves explaining, misdirecting, denying — whatever it takes to address every item on his grievance list. Which is as long as his tie.

Trump will certainly check the “consistency” box: He will be the same on Tuesday as he was two Tuesdays ago, as he was in July, as he will be in October. But that person is losing. So he has to change the trajectory of the race. In the context of the debates, there are two simple ways to accomplish that: by doing really well and/or by forcing Biden to do very badly. (Curiously, Trump’s overall strategy has been to hope for Biden to make enough unforced errors for Trump to win. Setting aside the likelihood of any debate moment being so catastrophic that Biden couldn’t recover during two more debates and a month of campaigning, it’s an awfully passive plan.)