trotting out "Biden was senile!"
That is a rather emotional characterisation, attempting to ridicule legitimate concerns without actually addressing them.
Terms used include "Diminished faculties", "Elderly man with a poor memory".
Technically it may have been "Mild Cognitive Impairment" (MCI). A clinical term for the stage between the expected cognitive decline of normal aging and the more serious decline of dementia. Not something you want in a president, let alone somebody just starting a 4 year term. And the swinging voters (you call them independents?) could see that plainly, even if the True Believers could not.
But right now, you are probably yelling in your head how he was "better than Trump". That tribalist instinct misses the whole point. There were countless people better - including Harris, who would have had a chance if she was nominated from the start.
All the "yes men" persuaded him to run again, to preserved their own jobs. And the result is what we see now. Another stupid war.
You're doing Republicans work for them! You helped Trump get elected!
Funny .. thats exactly what I said about the Democrat party. I'm just an observer - you can't hold me responsible for their failings. It was the denial on the Dem's side that gave Trump such an easy victory.