If Biden refuses a debate with Trump, that just indicates the man is mentally "gone".
@D o C ....
If I were one of Biden's handlers, I would make up whatever excuses not to debate. When you have the lead in most polls and Trump just keeps talking stupid, let him talk.
As I noted the words of Mark Twain earlier, "it is better to remain silent and be thought a fool than to talk and remove all doubt."
I would tell Biden to stay in his basement and let Trump talk about curing COVID-19 by ingesting disinfectants or swallowing UV light bulbs.
When you're in a fight and the other guy just keeps punching himself in the face why get involved?