If that is the case then Indiana is a lost cause. An endorsement of Pence may be what it takes to get him out of office, too. That's a double edged sword, considering that Trumps a maniac and it could reflect poorly on him, too.
Not this year. It is a numbers game, and he only needs to hit the right numbers one more time. Trump voters are the Rs that'll be at the polls. He'd be foolish (and he's really a pretty smart guy, sometimes too smart by half) not to get a Trump endorsement. Just like Gregg would be foolish not to seek a Hillary endorsement.
This cycle is about the fringe. There is no middle.