These Republicans' main objective is to destroy Trump by pushing the narrative that Republicans are against him, that's he's going make down-ticket Republicans lose...so the establishment can have something to pin on conservatives in the next race. Meanwhile, Preibus pretends to be above the fray calling for unity.
Trump is being sabotaged by members of his own party. If he loses, the Republican Party is FINISHED.
Priebus came out today and gave a rousing, enthusiastic speech and introduction to Donald Trump at Trump's Erie, PA rally. Priebus hadn't previously been scheduled, so it looks like he did it specifically to show support for the candidate and to shore up the party.
Those signers are a bunch of has-beens; think Karl Rove only a tenthof one percent as influential. The real story is how far down the media is willing to dig to try to discredit Trump.