Whether the RNC sees Trump as a threat to the establishment GOP or just a bull in the china shop, if he doesn't get the needed delegate count, the Convention will nominate another candidate. One that toes the line of the party. Good or bad, it's much like union power. They cannot "disenfranchise" (a term liberals love to use) voters if half the votes say they wouldn't vote for him if he was the nominee. The RNC wants to win, are desperate to win this term. They won't have to sneak Kasich in. He is visible to the country and is liked by enough that they think that out of the three, he is most likely to win against Hillary. It is their prerogative to nominate whichever representative they wish for their party. Just like the DNC has already decided that Hillary will represent them. It is just a matter of her coronation. She already has the super delegates, so Sanders is just so much window dressing. I bet they are surprised that he even fared as well as he has. The majority of Republican voters as well a a good portion of Independent voters would rally around Kasich. Hillary would have no ammunition to use against him. She would defeat herself, IF she is not incarcerated first.