I like Condi Rice because she is successful, talented, and powerful, but people around me can't fathom the fact that she's a Republican. They can't warm up to her as a result.
The Republicans on the other hand, seem very hateful towards Hillary Clinton, not just because she's a Democrat, but because she's a powerful woman. They know she is ambitious, and in fact, many people are certain she will make a go for the presidency in 2008. Hillary is therefore more of a threat than Condi and I think that is the reason for the animosity towards her.
Our culture is more afraid of powerful women in general.