Threats of violence from his supporters pre-dates the 1-6-21 events. It was "baked into," their relationship.
Speaking to Breitbart News, (March 13, 2019) Trump said:
“I can tell you I have the support of the police, the support of the military, the support of the Bikers for Trump – I have the tough people, but they don’t play it tough — until they go to a certain point, and then it would be very bad, very bad.”