@rosborne979,
I think there are three reasons that they are repudiating him:
1) More than anything the man is an obvious joke to all but his inordinately uneducated followers. Even if he were a political fit the man is a joke.
2) He is not a political fit. The trade war rhetoric is a shitty Democrat argument (that they only use to get elected, they don't' beleive that nonsense either) and he is not a good free market capitalist because he is raving economic nonsense.
3) Despite the Republican party having a long way to go on social issues they aren't a monolithic party of troglodytes that their opponents would like to see them as. Many of them are legitimately appaled by his distain for women, and his demagoguery.
4) They see him as inevitable to lose (due to all of the above) and don't want to back a temporarily popular loser (they might be misreading Trump's rise like everyone else has given its inherent unpredictablity).
If he were an "establishment candidate" he wouldn't have a lot of these legitimate downsides they have with him. It goes beyond him being "anti-establishment", the man is clearly one of the worst mainstream candidates to ever come along, whose popularity is an artifact of dissatisfaction with poltical obstructionism.