Don't try to take the politics out of politics. Sen Cruz is an extraordinarily bright guy, with a tremendous resume, who sensed he had a shot. Ambition and history demanded that he take that shot. I don't hold that against him.
I hate to say it, but the failure to keep him out of the race...
Lesson Number One: When federal investigators, be it from the FBI or US Attorney's office, or whatever, start asking you questions, you shut the hell up and wait for your attorney...