Then, around the corner, gliding noiselessly, came dementors, ten or more of them, visible because they were of a denser darkness than their surroundings, with their black cloaks and their scabbed and rotting hands.
A precursor to vaccination as we know it today, variolation involves grafting smallpox scabs onto healthy people to give them a milder version of the disease, with the hopes they'd be immune afterwards.
And then this typical rash develops, which is sort of pustular in form, and that's usually what's infectious, and this is infectious until the scabs actually fall off.
Donald Trump has ripped of the scab of the nation's racial politics, emboldening a kind of overt racism that many convinced themselves had been banished.