I agree - mean spirited. Just showing his behavior and comments would be enough and let the reader make their own judgements.
Regarding the reporter asking about the cognitive test, I thought the worst part about that (for Biden) was bringing up drugs. Voice-over should have been something about the race/drugs/junkie thing. The reader can make up their own mind on how crazy Biden sounds.
OTOH - I thought in the 2016 election Trump was being too brash, etc. But it worked out okay for him.
But the hair sniffing is not about his mind per se.