Believe me, Ted Cruz is not a change agent.
Maybe not
But we’ll ignore the fact that he took on the Senate over Obamacare with the unpopular mandate that Trump said himself he liked ;)
But Ted has been setting up this run since he entered office. It was wise political maneuvering, and I don't know why more 'conservatives' in the congress didn't move that way, but it was grandstanding, building a foundation, accomplished nothing - he wasn't able to rally enough support to actually get anything done ... but let's say Ted is totally sincere - that he really thought he could accomplish something, rather than just make a name for himself reading Green Eggs and Ham.
The desire to change is not equivalent to the ability to change. Ted has only been effective since he married the establishment against their will. Without them, no Wisconsin, no Colorado. They need each other. The bad side of that equation is that Ted needs the establishment - he's dependent on the enemy.
So I get where you are coming from, but I don't buy it - I think Ted plots for himself first, America second, if at all. I think he might believe he's doing wonderful things for everybody. Certainly he's arrogant enough to believe that.
Give him time to mature as a politician and reveal himself, and for America and him to figure out who he's really for. Or not, of course.