You seem to be saying that Cruz is out because he is working in the senate, the only viable candidate has no experience with the Federal government?
Unless you WIN, the "experience" doesn't help, and in Walker's case, even when you win, you need to show that you can ratchet up that state-level victory to national concerns (which he certainly has not done).
But I'm just suggesting what I've heard some here in middle America tell me. Who knows? Something explains his 4-8% ditch, which he can't seem to get out of.