Trump's 'infested' tweets violate a very specific Twitter rule

Rats, rodents, maggots, crime. These words have literal meanings, but when they're used to describe specific places or groups, they take on something more.
It's something CNN anchor Victor Blackwell pointed out in a moving segment about Trump's racist use of the word "infested" in tweets — and also something that Twitter explicitly prohibits in its rules against "dehumanizing language." 
It's no secret that Trump walks all over Twitter's rules against racist verbal attacks &mdash