Sometimes loyalty is a vice. If McLame called her personally, it certainly would be very hard to say no. After all, in a very perverse way, McLame is responsible for her current favor.
Yes, I can understand why she could not say no, but do not like it. She is still making a mistake here...and will face a bit of fallout with her fans. Hopefully, McCain will lose big and have no effect on her support, but that is just a bit optimistic. Even if he loses, she will feel a bit of the fallout (and really, she should). She is going to make mistakes, but this one was easily avoided - she chose not to.