Honestly, IMHO, she's already decided not to take the job and it's her thinking in hindsight about Senator Bracken that's allowed her to make that decision. She realizes that if she were to take the job, it would allow her to pursue him and she's probably worried that it's the only reason to take it and it takes her a bit to realize that and that it's the wrong reason.
I don't think the writers even remembered the senator at this point. My thinking is that she decided to stay when she made that speech about the interrogation room being her home. That sure sounded like she was realizing she was already where she belonged.