He is crappy on amnesty. The only thing holding him back. However, he is damn good on almost everything else. Plus he is battle tested, being targeted for death by the democrats 3 times in 6 years, and he has beat them every time.
Walker is weak on amnesty, he has provided NO support to Ted against Obamacare and in defending the Constitution, he is great pals with GOPe sellouts (Priebus, Ryan, Rove, and Romney), and he is loose with campaign promises he does not fulfill.
So Cruz is the only one who holds right positions on everything.