The anti-Palin rage was exacerbated by the Romney people, but I believe McCain himself harbored resentment and envy in 2008 as well.
Because he KNEW that she was the life-blood of his campaign!
Until he brought her on, he was losing and looking like a complete WIMP!
So, when she skyrocketed to the front and he knew that SHE was the cause for his gains, he became resentful and envious!