Not sure where you're seeing that. Many prominent Republicans have endorsed Trump, but then denounce comment after comment Trump makes, without ever removing their endorsement of the candidate out of loyalty to the party.
The "problem" for Republicans is that at least 1 and possibly up to 3 supreme court seats are opening up within the 4 years. Presidents come and go, congressional majorities ebb and flow, but if the Democrats get to seat 3 new justices then they might lose the Supreme Court for a generation, and the Republicans care a lot about the supreme court. So the question is not who will be the better president, but who will select the the 'better' supreme court candidates.
They might disagree with him on many things, but I don't think they think he's outright unfit. It seems to me that they still sincerely think he's the best choice when the other one is Clinton.
In any case, it's the electorate that really matters, not the leadership. I don't see any prospective voters afraid to speak their mind. Trump supporters among the general population all seem to be completely sincere. Trump opposers are unafraid to declare it.
> "He needs someone highly experienced and very knowledgeable because it's pretty obvious he doesn't know a lot about the issues," McConnell said of a running mate for the mogul.
He doesn't say he is "unfit" because he can't -- How can you not think a comment like that from McConnell is pretty damning of Trump's abilities?
You are coming close to claiming that vocal people are the ones that are vocal. How much of the electorate has not said anything to reveal their position (and how important are they when it comes to the election)?
In past elections, you'd always have people saying they were undecided and that they liked this aspect of Candidate A but that aspect of Candidate B, or similar.
I'm not hearing that this time around, except for people who are basically saying "I can't believe I have to choose between these two, I think I'll just stay home and get drunk on election day instead."
Perhaps this is just a reflection of my memory or my media consumption. But that's why I started my comment off with an explicit disclaimer that it's just about what I've seen.