Last night at the debate, Trump specifically attacked Cruz and Rubio for being in the pockets of special interests... but "not the Governor." Kasich wasn't just left out of the attack; he was specifically excluded.
Trump has given hints as to who he'd pick as a running mate. He said he would pick a politician... "We don't need two of me." and he said logic would dictate someone from a battleground state.
Kasich is generally well liked within the party. He's held up fairly well in the campaign. He would "unite the party."
PLUS, if it’s a deal before the convention then Trump will have his delegates and the GOPe can go pound sand.
Not to be paranoid but....
Trump must pick a VP who is sufficiently repugnant to the power brokers that a coup would not be a good idea.
We don’t want the power brokers to be better off with Trump elected, then dies in office.
That is a basic starting point if you are Trump and the Bilderberg crowd has a lot at stake.