“...like he has to get a memorized speech out of the way?”
So you noticed it too. While he was talking to Hannity, he said, “I am the only one left who can unify the party”, overlooking the fact that most are still in the race. He is so attached to his talking points that he gets confused and got ahead of himself. He must have a stock ready to go.
Somebody is coaching him. It’s not only the speed but the glib, at times robotic and scripted answers. He just is not credible.