The rasp in his voice also makes me believe the explanation that he had some form of cold further hampering his performance.
That's still bad for a president, but it is workable.
I still think a Biden candidacy and presidency could work.
Still, the debate has shaken the public's confidence in Biden's cognitive abilities to the point where I do think a Kamala Harris campaign is marginally the better option.
I say that as someone who considers Biden the best president in my lifetime (which started in the Clinton administration)