"If Cannon had all this going or him, how come an "unknown" defeated him 52-48 at the Republican nominating convention?"
You obviously know all the local details much better than I do. So you know the answer to your own question, and I do not.
These types of efforts usually fail, because of incumbency, name recognition and money disparity.
If the incumbent has perfect ACU ratings, the opponent is grasping at straws to show Cannon is not a good conservative.
That makes it hard for this outsider to see why the convention voted as they did. Often it is local party infighting, other local officeholders jockeying for power, etc.
Whatever happens locally, please don't open the door for a democrat.