“qualifications to do the job of President? What has he done that shows that he has the executive experience to run the government?”
Let’s hear who you think meets those requirements.
My choice would be a governor (no, not Christie or Bush) who has governed fairly conservatively. In no particular order: Pence, Kasich, Snyder, Martinez, Jindal all come to mind, but there are undoubtedly others. Are they perfect? No. But they understand how to get things done in a republic (unlike the current resident of the White House). It should be the job of the legislature to "get things done" (or not, if it doesn't need to be done).
My worry is that Cruz, like a lot of conservative senators and representatives, doesn't understand that the President proposes ideas and Congress should then act on what they see as appropriate (within the confines of the Constitution).