They are immune to reason. They live in a different dimension than we do. They are immune to reality.
In their reality, a candidate who receives a third of the votes in the primaries is strongly opposed by roughly two-thirds of the party's membership and fails to achieve a majority of the delegates in a series of fair primary contests is nevertheless entitled to the nomination. But only if it's their candidate.
In their reality, if a candidate has proven to be "the people's choice" (which Trump, of course, has not), nobody has a right to oppose him. As long as it's their candidate.
In their reality, a candidate who lies almost as often as he breathes, inherited his wealth, has failed repeatedly in business, knows practically nothing about the issues or even the most basic facts of American government taught in Civics class in high school, knows everything, is always right, can do no wrong, and is the ideal president of the United States. As long as he's their candidate.
In their world, manners don't matter, basic civility is to be demanded only from their candidates' opponents and never from him, and their candidate is free to say anything he wants, no matter how outrageous, and somehow reality becomes what he says it is.
One cannot reason with them because they are immune to reason. In their dimension, different rules apply.
In their dimension, if the polls say that their candidate is going to lose, the polls are rigged. In their dimension, if what their candidate says doesn't correspond to the facts, the facts must be wrong.
So the obvious question arises of what they're going to do and say when- not if- Donald Trump, having been nominated, goes down to a historic, landslide defeat at the hands of a woman who to all appearances ought to be in jail rather than in the Whtie House. Three approaches will probably predominate.
The first one of The Donald's own favorites: that somebody else is responsible for their own blunder (this includes the notion that nobody has a right to disagree with them, and therefore that no Republican has the right to vote for somebody else or even to stay home.
The second is that the election their guy lost by a landslide was somehow stolen.
And the third is that reality is wrong, and President Trump really won,