The question you ask is the most important question in America right now. I don’t know anyone in the major media asking it in any clear way. Pretending this can’t happen does not make it go away.
We have been repeatedly warned about the complete internal focus of psychopathic narcissists. We have been warned by people who were close to Trump. He, himself, is unable to NOT tell us what he will do.
His followers are now as mentally disturbed as he is. That is the process by which they are turned into weapons. As you note, reality has been completely abandoned.
There is only fear and anger which demand destruction. Trump half heartedly read a prepared statement on the Christchurch slaughter and then repeated the killers language. He, as many powerful cowards do, does not order things to be done. He rewards those who do what he wants without orders.
He is now waiting for them to act. No one wants to admit this so nothing will be done.