I don't doubt that Rufus demonstrates that she's done something to change him. He's clearly very sympathetic toward her, goes out of his way to keep her close to him, and makes an effort to treat her with some respect. Still, this only points to Dana's ability to make Rufus like her. She's failed to make any perceivable impact on his idea of a trusting relationship. He seems to have some underlying abandonment issues, demonstrated by how his relationships are always completely dominated by him. I don't think he can even begin to conceive of one where he isn't the power figure. He will never restrain himself from trying to get what he wants, no matter how much it will hurt others, and it makes me wonder what exactly it is that Dana's done to alter his actions in any way. He feels his love for Alice should be enough justification for her rape, and his more platonic love for Dana should be enough reason to force her to stay with him.
Rufus' lack of a conscience is pretty sickening, and Dana clearly feels the same way, yet she always seems to give him the benefit of the doubt at just about every opportunity. We saw this especially when she accepted that he had sent the letters, even when she had been warned he probably didn't. She feels a familial connection to Rufus and sees some hope for change in him, despite all evidence to the contrary. Rufus trusts Dana but completely takes her for granted, and Dana interprets his confidence around her and politeness toward her as her making a positive impact on him. I can't help but roll my eyes a bit every time Dana finds herself surprised at Rufus' harsh actions, thinking that she's figured him out. I definitely take his behavior to be more indicative of the fact that he has power over her, is used to having this sort of power over people like her, and has no intention to give it up.
I imagine Rufus will remain a fairly static character throughout the course of the novel and Dana will eventually have to accept her failure to change him.
I imagine Rufus will remain a fairly static character throughout the course of the novel and Dana will eventually have to accept her failure to change him.