Even though Hillary will probably win significantly and if she does any other sane Republican opposition would concede an election in a heart beat as is the American tradition it is different for Trump and his supporters who have no hearts. He will do anything to stick it to the nation he says he loves and better still he will do anything to hurt the Republican Party who has only itself to blame for this Frankenstein monster whom it created but who will kill it first.
In addition to the chasm in the Republican Party that has existed for quite some time there is another gum-up-the works tactic about which they must significantly worry. Rachel Maddow talked about a "Consent Decree" see http://www.msnbc.com/rachel-maddow-show in her video segment entitled "RNC in legal trouble over Trump call for poll-watchers."
Briefly, the Republicans are under a Consent Decree order from the court barring them from trolling the polls or "monitoring fraud" a/k/a "Poll Watchers" as they promote their preventing election fraud fraudulent agenda. The Consent Decree has been in effect since 1981 when Republicans "monitored" polls with phony ID's and signs to allegedly catch them in the act of committing election fraud. Who is them? Do they watch heavily Republican polls? Heck NO only those polls with a heavy African American and Democratic turnout. It is yet another voter suppression technique Republicons carry in their suppress-the-vote (the Democratic vote) democracy destroying and Republican election winning nuclear weaponry arsenal. Ironically, though fraud is rare, its business of fraudulent fraud catching is booming in Republican Gunsmoke land and those John Wayne Republicons are going to catch the bad guys -- only Democrats, of course.
Every time Drumpf tells his supporters to monitor the vote he is violating the 1981 Consent Decree ordering them to cease and desist from poll watching that is monitoring and intimidating black voters to suppress their vote i.e. the Democratic vote. If they violate this order, which I am sure they will, instead of it expiring in 2017 it will expire in 2025. Republicans want desperately for this Consent Decree to be removed but Trump is foiling their chances and the RNC is going berserk over it.
The threat is that the RNC will pull away from Trump and say to the court they are not connected to him. Just how they are going to do that I have no idea. Perhaps it is another trick in their bag of many tricks. BTW, Democrats have already filed a suit against the RNC because of new poll trolling attempts complete with green Pepe the Frog badges, a symbol now of white supremacy. I cannot wait to see how that goes down in Little House on Republican Land!