If he does drop out of the debate again, I bet they could get him to recommit by going all Biff Tannen on his ass:
“What’s the matter McTrump? Chicken?”
He’ll bristle, and say he’s no chicken and agree to debate Kamala.
In all seriousness, I was surprised agreed to debate her at all, given that he has nothing to gain. Best cash scenario, he tries the same approach he used with Biden, turning his mouth into a fire hose of lies, and Biden couldn’t keep up. With Kamala, she’d just laugh at his lies, and actually refute him with facts, he’d look just awful in comparison.
At this point I doubt he’ll actually show up to the debate.