He is. And as someone who debated in high school I can tell you that it's stressful enough with only a win or loss on the board. August 6 will be make-or-break for easily half the candidates on the stage and someone like Cruz, with his bacground and experience, will shine. Most of the rest will not. They will have their own "oops" moment like Perry did. Or they'll ramble and stumble and not get their message out. But Cruz will excel.
When a dedicated left winger like Alan D. calls Cruz “brilliant”, it might be time to pay attention : )