Found at AOSHQ:
The real reason the elite hated Donald Trump was not that he was an ideological conservative (he only sort of was) or that he tweeted mean things (they like mean tweets, just not ones directed at them). It was that Trump identified the failures of “the best and the brightest” and called them out. There is nothing these experts hate more than challenges to the authority they think they deserve. --Kurt Schlichter
And the reason that Trump was despised by most members of Congress? Sort of the same thing: he looked at a problem and solved it, right then and there. Congress religiously avoids solving problems as a matter of self-preservation. How else can you get re-elected but to have problems?