At the start, DJT should casually, off the cuff, suggest he and Biden pledge allegiance to the flag. There will be one on stage, and why not?
That alone will throw Biden off his game for the entire debate.
Even if (Big IF) Biden successfully recites the pledge this time, he will think - throughout the entire debate - that the whole world knows how he just screwed up the pledge last week (for real) and that alone will mess with his mind and preoccupy his whole thought process for the entire debate.
I doubt he remembers that far back.
I like how you think!
Except, he wasn’t trying to recite the Pledge at that time.
“Think about what he’s saying,” Biden said. “He’s saying if you live in a state like Wisconsin, Michigan, Pennsylvania, states with Democratic governors, you’re not his problem. He has no obligation to you. He’s not responsible for you as President, your family or your well-being. I don’t see the presidency that way. I don’t pledge allegiance to red states of America or blue states of America. I pledge allegiance to the United States of America. One nation, indivisible, under God. For real. I’m running as a proud Democrat, but I’m not going to govern as a Democratic president: I’m going to govern as president.”