I see it this way, Trump has to dance on the head of a pin because he is running for Potus in a party that is filled with fair weather friends and outright enemies. We can say the truth without consequence. Johnson is a traitor and a dirty coward. We can only hope Trump sees this but is playing the long game.
Well, I can’t find much to disagree with what you said.
Trump has no problem talking truth about the border and if he thinks talking border security will jeopardize his election chances, then he has already lost.