"You don’t need to be a psychiatrist to understand that the kind of hate and fear-mongering that is the stock-in-trade of Mr. Trump and his enablers can goad deranged people to action. But psychology and neuroscience can give us some important insights into the power of powerful people’s words.

“We know that repeated exposure to hate speech can increase prejudice.... It can also desensitize individuals to verbal aggression, in part because it normalizes what is usually socially condemned behavior.”
Article: The Neuroscience of Hate Speech