He knew what they were going to do. He knew he stood nothing to gain from this. Giving their propaganda system another high profile stage to attack him was a mistake.

And this is one reason why he's a retard. He fell for the most obvious fucking trap in existence, because he can't control his ego.

All he had to do was show up, hammer harris on the economy and border, and blast her for her failure to control the border. And instead he gets fucked by his own ego and lack of control