Rosie O'Donnell can't stand Star Jones for pretty much the same reason Ozzie Guillen hates Jay Mariotti.
I seem to recall reading a quote that Rosie "had the ass, big time." So there are some similarities.
Seriously, there are some similarities between the Star Jones-Rosie O'Donnell feud and the Jay Mariotti-Ozzie Guillen showdown.
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O'Donnell is a mean-spirited, popular lesbian. Guillen is a mean-spirited, popular manager willing to slur the gay community to make a point. Jones and Mariotti are both looking for victim status, and they've been excoriated by their peers.