With the Trump candidacy showing no immediate signs of ill-health, we begin to see the GOP elites, the donor class, and the punditry start to cope. You gotta know they won't back Hillary, and they won't start a 3rd party movement, leaving only two choices: stay home or get on-board.
As several have noted, the elites are proceeding through the Kübler-Ross five stages of grief: denial, anger, bargaining, depression and acceptance. Their denial has been well-documented, as has their anger. Some evidence of bargaining has already surfaced, along with depression.
Between now and the effective end of the primary season we'll see if they go the whole five steps to acceptance. If Trump flames out, they won't have to eat that final portion of crow labeled "acceptance" and will, I am certain, deny any bargaining that preemptively took place.
My crystal ball is "in the shop." I don't know whether or not Trump will win the GOP nomination. Whatever happens, he will have made the 2016 race more interesting, fun, and arguably more consequential. Watching the supposed "elites" squirm has been a lot of that fun.