And an expert in political violence and terrorism is worried the worst is yet to come.
The justification of political violence online is getting worse, too, with increasingly high-profile people laughing off violent incidents.
Plenty of such data exists about Trump's rhetoric, Pape noted, and he said there is no doubt that "incendiary political rhetoric increases support for political violence."
"What you're seeing is real-world violence reflecting this significant rhetorical support for political violence on both the right and the left," Pape said.
"There is an incentive to do what we know stokes support for political violence.
Persons:
—, Robert Pape, Pape, Nancy Pelosi's, Barack Obama's, Donald Trump's, Steve Scalise, Elon Musk, Sunday's, Trump, haven't, Joe Biden, Kamala Harris, Musk, snickering, " Pape, he's, Biden, stokes
Organizations:
Service, World Justice, Democratic, GOP, Business, Democrat, Republican, Marist, PBS, Chicago Project, Security, University of Chicago, Department of Justice, Congressional, Trump, Republicans
Locations:
Louisiana, Butler , Pennsylvania, —