Seems like a stretch for these wealthy elites who run everything to run around worrying about the "death" of the political party they own seeing as how they're still wealthy elites and are running everything.
Probably the best thing for them to do is take a breath, let Trump be the nominee, watch him lose big and then begin the long "I-told-you-so" campaign. Meanwhile the party still controls the congress and most of the state legislatures. Even without the White House, they're still in control of the agenda in most places. Plus they get to keep playing victim to Big Mean SocialismNaziLady Hillary for four more years.
And we haven't even mentioned the fact that the Clinton Administration will be mostly friendly to them anyway. Nothing has to change for these people at all. Why are they even complaining?