I was a fan of Sara long before the us vs them attitude; but I think the thing is that a lot of Jen/Dale etc fans will be supporting her because they want to see somebody outwith the B-Block group win. There are the sympathy votes, as you said, but also people like myself (who I believe make up the core of Sara supporters) who find her to be the most genuine, fun loving housemate in the house.
I don't condone the way she led Darnell on, but I think she was a bit naive and not entirely to blame for her actions but it was the diplomacy with which she handled all his insults that I thought to be a true test of her character. Kathreya cries over much less, Rachel gets worried about this sort of thing but neither would stick up for her, despite professing to be nice people. She didn't have anybody to stick up for her but she still refrained from being bitchy or resorting to insults in return. THAT is why I think she should win.
