Candidates Trump Has Attacked
Candidates Trump Has Not Attacked
The list shows that there are four candidates that have not fought with Trump. Trump will not pick Santorum because he is not a strong candidate and will not pick Chris Christie because of his baggage and also their personality's will not work well together.
Now of course Trump can pick anybody to be Vice President. However he probably won't pick a Governor or a Senator who endorsed another candidate. Huckabee is a southern conservative and former Governor of Arkansas. He is not part of the Republican establishment and is seen in many aspects as an outsider. Trump and Huckabee seem to have a friendly relationship. Yes Huckabee is not polling very high nationally or polling high in any of the early states. With Huckabee on the ticket it would bring a different personality to the ticket, a qualified Governor who could be President, and a candidate who is well known who does have a following when Ted Cruz and Ben Carson are not taking it. Huckabee also does well in the debates. He knows the issues and comes up with some pretty good lines.
The basic point I want to make here is that out of all the candidates running for President only Ted Cruz and Mike Huckabee could be Vice President.