Political professionals have gotten so much power in presidential campaigns that they have diluted the candidates of a message and put up barriers to getting votes. They convince the candidates to run from most media interviews for fear of a gaffe (making them ultimately more gaffe-prone since they get rusty), stick to a boring, limited stump speech to give their talking points more resonance (even though saying something in a new way is more potent), and slice and dice the voters so that virtually everything the candidate says is geared toward an interest group rather than the electorate per se.In other words, Cruz followed the playbook like the good student he is. But he didn't break through to enough people because he was fighting the last war.
Why? Being stage-managed gives more power to the consultants. It makes the candidates more dependent on staff and vendors to navigate them through the torture chamber those people make the election into. The consultants become the smart people and the candidate is a commodity. This attitude is shared by the political media, whose access to the candidates is dependent on sharing a worldview about campaigns with those consultants.
It's giving Trump too much credit to say that he meant to expose the stupidity of professionalized politics, but that's what he ended up doing. And he got lucky in the sense that his final primary opponent – although in just about every other way the type voters were looking for in 2016 – was somebody who leaned on that professionalism.
Cruz is a young man and will have another chance to run, likely as soon as 2020. If he learns from his experience, he'll be back. But I do think it's just about over now.