Unfortunately, it's not just leftists who would vote for her. There are enough people who would vote for her merely because of her sex to take her over the top. Further, she is viewed by many as a "moderate," (which says more about what the media considers moderate than anything else). There will be no scrutiny over her past. She is such an effective communicator, and if you don't believe that, recall how many here at FR thought Lazio had a real shot at beating her.
She's dangerous, more so this year than at any other time. The key to winning this one is to play Kerry like a fish until the very end.
All polls I've seen show Bush beating Hillary far easier than beating Kerry. Much of media does indeed attempt to portray her as a moderate, but not enough people buy into that nonsense to put her over the top in a general election, imo.