That is a real problem for Biden. Biden has been coasting by relying on long term recollection of old campaign memes and soundbites, entrenched from many years ago. We know long term memory is resistant to dementia until the late stages, so he gets away with it. Political demagoguery sounds the same now as it did fifty years ago. The average listener won’t know the difference, and the media won’t tell them.
Biden can’t remember names. Hit him with names and he will blank out.