@hightor,
Of course, this study doesn't prove anything and the notion of the Trump being a "social contagion" is particularly specious.
Still, it isn't surprising.
Do you think that if the Trump rallies weren't being met by violent, obscenity hurling protesters the participants would have been walking the streets looking for people to assault?
I don't condone violence as a reaction to anything other than violence or threats of violence, but I can understand why someone might feel the urge to slug someone who spit on them or called their wife obscene names.