Not sure why - they pretty much agree on every issue. Is it because Walker is a lot more stupid than Cruz?
No, its because Cruz scares me. He's got that wicked snarling face, he reminds me of Joe McCarthy. I wouldn't trust him to mind my dog, let alone run the country.
Scott Walker is on the far right, but he's very low key about it. IIRC he's just as evangelical as Cruz is, but Walker is stealthy. He makes very bad policy decisions but you don't see him defending them in public like Trump & Cruz do.