On the other hand, it was a stroke of genius for the Trump people.
If (remote as it may have been) Cruz had endorsed Trump, it would have been a positive for both (Trump +1, Cruz +1). If as what actually happened, Cruz refused to endorse Trump, it would still be a net positive for Trump (since he graciously let Cruz have the floor), but a big negative for Cruz (Trump +1, Cruz -1).
Perhaps he was saying to himself I am not endorsing him, which of course was wrong.
“...stroke of genius for the Trump people...”
I agree. Brilliant. By allowing Cruz to speak they handed him the proverbial rope to hang himself with metaphorically and Cruz so foolishly went ahead and hung himself as far as political reputation forever because his ego was too big to even see what was happening.
He should have listened to Laura who gave him the correct advice earlier on but he was too full of himself to take it.
Checkmate Trumps.