Priebus did his job to the letter. He backed nobody in the primaries and went all in once Trump got the nomination.
Maybe he is in over his head and maybe he isn’t but I’m willing to bet he’s one of the good guys.
I have no sense of whether he is a good guy or not. He was an excellent election strategist, based on everything I know.
Perhaps he is a great guy. Perhaps he is simply an opportunist. I wish I knew.