I don’t see Trump picking Cruz as a running mate, if the two of them even stay in the race that long. Each man is very similar to the other in certain ways they handle the public and with their erstwhile conservative messages. Donald can be so in your face confrontational, that I think he would be advised to pick someone who appeals to people that do not care much for Donald.
I suspect he would pick someone very well spoken, and professional in demeanor. Someone less known for rocking the boat or destroying the boat completely. Donald his almost 70 y/o Seventy! He will wish to offset his age with youth. Think of the poorly treated Dan Quayle.
I think Donald will have his 12 year old son call up one of Marco’s sons and invite him to a soccer game in the neighborhood. Marco’s first impluse will be to say (Hell!) no, you can’t go to any ball game with Trump’s son. But then, by that time, Marco would already have run out of money and left the race, so he’ll think it over, and agree.
I do. Trump's the outsider. He needs someone who knows the Washington ins and outs. Kind of like Bush and Cheney. And that would make Vice President Cruz the logical pick after 8 (or maybe only 4) years of Trump as president.