Until the Trumpster reaches 1237, it's game on, whether you like it or not.
Or, to repeat what Trumpeteers have said to me: Toughen up, Buttercup.
If there is a contested convention, Trump will go in with the most delegates, the most states won, and the most votes received--by far. The "game" will be over for the GOP if they select someone else.
Trump is the reason that primary turnout records have been set. He is the person responsible for the huge debate ratings. He is the one setting the agenda for the campaign season, e.g. immigration, trade, treatment of the veterans, etc. If anyone thinks that the Trump voters, the most committed, enthusiastic, and loyal will accept someone else getting the nomination, they are delusional. It will be game, set, and match for the GOP in November if they select someone else.