Romney was a charter member in the government gravy train - and he would have kept the corruption rolling right along. He was establishment. So the rest of the establishment and the media were comfortable with him. He rocked no boats and would have changed nothing, except around the edges of a few policies. That is what is what is offensive to the establishment and the establishment media about Trump. He promises true, revolutionary change to the government - he will attack the endemic corruption that the establishment wants desperately to keep in place.
OK, that starts to make sense then. Trump is anti-Washington, and that scares even many in the GOP. That is what this is truly about but they are pretending that Trump is “dangerous” as a cover to their opposition.