Hillary Clinton is a monster. She's a crude parody of feminist progress trying to turn the United States into a parody of democratic republicanism like Pakistan and India are. In Pakistan a 19 year old boy is the leader of the leading opposition party because of his lineage. In India an Italian woman is the leader of the governing party (but has the common sense not to serve as president or prime minister) because of the family she married into. Senator Clinton's claim on American votes is little better. She is a monster like George W. Bush is, like Teddy Kennedy was before voters repudiated him in the 1980 primaries.
Samantha Power wasn't talking about any of this when she called Clinton a monster. She was apparently complaining about the Senator's campaign tactics, and as an adviser to Senator Obama she came off as a whiner -- if only because her interviewer refused Power's explicit request to keep that particular comment off the record. The Obama campaign isn't supposed to whine; that's what the Senator himself says. So it was probably right for Power to go, not because of what she said about Clinton, but because it was bad form for her position. But with all that being said, Hillary Clinton is a monster. There may be worse monsters out there, and we may yet be forced to choose among monsters, but we shouldn't have to hold our tongues while we hold our noses.