He delivers Florida but can't win its primary?
He is an amnesty pimp, and Trump's position on illegals is the main reason to support him in spite of his rather recent conversion. It would be insane for him to put doubts into the voters who he has made all those promises to. He needs to pick someone who stands with him 100 percent on the big issues his backers care about:
Illegals and the wall;
Obamacare being repealed in its entirety;
Muslim immigration being stopped, and refugees sent back;
Trade deals being nixed in favor of America-centric ones;
Taxes reduced;
Protection of 2nd Amendment;
Taking care of Vets;
Kicking ISIS' ass but not going on foreign adventures.
Rubio would show it was all a ruse. Bush as VP was Reagan's worst mistake, but picking Bush did not indicate that Reagan wasn't sincere. He had a long track record. It just meant he was playing politics. And it came back to bite the country 8 years later. Trump picking Rubio would put the GOPe in the henhouse, and it would discourage the voters that made Trump's movement in the first place.
I think he is smarter than that.
I'd like to see Cruz, if they can still work together, but if not then it needs to be a solid conservative to unite the entire party.
Believe me. You dont want me ruling the world.