The Republican Party doesn't have a valid path to the White House this year, and they've known it for a year, and they've spent millions having people research the problem. The problem they want to solve is that the Democrats have a two-deep bench of candidates who can defeat any Republican.
(The problem they don't want to solve is that their predatory practices have literally killed off a critical percentage of voters, and now the GOP has a difficult time winning statewide elections, much less a national one like the Presidency.)
Clinton, Sanders, and Biden have all polled higher than the entire Republican clown car, and Romney, and Ryan. Left to its own inertia, the majority of American people intend to destroy the GOP forever, before the decade is out.
So the American people cannot be permitted to decide.
Therefore the only chance they have is to fall back on the gerrymandered House of Representatives, and the only way they can kick the election into the House is by (also, secretly) backing a third-party candidate who can take electoral votes away from the Democratic candidate so that no candidate wins a majority of electoral votes.
At that point, the House simply has to do what they do best, nothing, and by not selecting a President the Speaker of the House inherits the office by default, without a theft-vote that would doom a hundred Republican Congressmen in 2018. This is why the incompetent and alcoholic John Boehner had to be maneuvered out of the Speakership. The next Speaker will be elected in January and it's important that the evil inner circle already has their guy in place before then--and that guy is Paul Ryan.
Republican voters are stupid but Republican leadership is diabolically evil. They have two paths to a contested election:
1) Steal it from Trump and he is guaranteed to run as a third party. Then the GOP can quietly toss money to Trump in the states that they think he can take from the Democratic candidate above the Mason-Dixon line, where only he has a chance of winning against, say, Mrs. Clinton;
2) Let Trump have it and allow the oligarchs to run an establishment conservative as a third-party candidate. Kasich would be a good choice because he has a chance of bagging Ohio and maybe other rust-belt states.
It's a dangerous game that, if not played well, would guarantee a win for the Democrats and might also lose them the Senate. It's a short-term gambit as well, because it's certain to add to the ranks of people who will never again vote Republican, like all of us. The movement in this direction is obvious to me and others, and we should be asking about the bigger picture at this point, because this is a works-once move that is unlikely to be duplicated in the future. So why would they do it?
Looking beyond this election at the next census, the numerous prosecutions for gerrymandering and election irregularity, and the increasing ability of statistics to correctly detect when votes are being flipped, it's clear to me that the inner circle of the GOP isn't just looking for a candidate that can save them now; they are looking for the last Constitutionally-approved American President, who will become America's first President-for-life. Their evil ways have consumed their own electorate, and the powers that be are increasingly looking for some sort of tryant that they can install so that their increasingly less effective election thieving can be replaced by the smoky backroom dealings that have always determined the course of the GOP and the United States.